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Chemistry | STEM | Grade 10 | LO2 — Transcript

by Dr. Mohamed Taha - Chemistry · 17,175 words · 2,657 segments · language en · Watch on YouTube

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0:05Peace, mercy, and blessings of God be
0:06upon you. How are you doing, guys? I
0:08hope everything is going well with you.
0:10This is the video for the part following
0:13the one currently being uploaded, right
0:17before our actual [lecture]. However, to
0:20make the [content] comprehensive and
0:23sufficient, I found the previous one a
0:26bit long, and. Likewise, you can listen
0:29to them while adjusting the speed to
0:32manage things.
0:34But it is important, because we are
0:35explaining it as if it were a regular
0:37part of the course.
0:38Or whatever method we are following, it
0:41is complete; nothing required of us is
0:43missing.
0:45So, we will start looking at [the topic
0:47] and get to know what is actually
0:49expected of us.
0:52What is required is for us to understand
0:54how the [atom] reached its current form
0:57; how did we arrive at this?
1:00I mean, how did it become the shape we
1:02know today?
1:03And what is this [atom] actually? It
1:07consists of...
1:09I mean, what is it, and what is it
1:10composed of?
1:12And also, we need to know what kinds of
1:14[reactions] will occur for us.
1:17For us, it is this image.
1:20An image where I have a sphere in the
1:21middle and things orbiting around it
1:23like this.
1:24And I don't know anything other than
1:26this view.
1:27For me, that is what the [atom] looks
1:29like.
1:31Well, let's trace the [atom] from a very
1:33long time ago.
1:34What led it to the [model] we know today
1:37?
1:39First, we look at scientists and
1:41philosophers from the past as they began
1:44to talk about the particles that make up
1:47[matter].
1:49We will take it from a very long time
1:50ago. The first person we have is a
1:51scientist named the guy in front of us
1:53who looks like [Adel Shakel].
1:55What was he telling us?
1:59He was telling us that, for him, the [
2:01atom] wasn't really his concern; he was
2:03, after all, a philosopher.
2:05But what did he say?
2:07He said, if I took anything in front of
2:12me, like a wooden board, and kept
2:16breaking it, breaking it, breaking it
2:20down into smaller and smaller pieces
2:24until I reached the smallest thing, what
2:29did he call this smallest thing?
2:33He said it is something that cannot be
2:35broken.
2:37In his language, the language of that
2:39time, what did it say?
2:42It meant that these things cannot be
2:45broken—meaning they cannot be divided or
2:48shattered any further than what I have
2:51reached; the word [atom] in that
2:54language is...It became its current name
2:57, derived from this concept: the
2:59smallest thing from the element or
3:02object in front of me that I can reach.
3:07Whether it's whatever, meaning you took
3:09an iron sheet, a piece of gold, or
3:10whatever else, and kept breaking it down
3:12, and breaking it down, and breaking it
3:13down until you reached the smallest
3:15point, what did he say this was called?
3:17It was called, so for me, what would
3:20that consist of? That firstly, it’s
3:23something that cannot be broken or
3:26divided, so okay, and secondly, it’s
3:29something what?
3:31Something, meaning it’s something in
3:32front of him like a grain of sand, so
3:33it’s something he is holding in his hand
3:35, meaning it’s what?
3:36Solid.
3:37And this was all that he knew about it.
3:40Well, after this, another person came
3:42named Aristotle, who is Aristotle.
3:45What was this Aristotle saying to me? He
3:47told me no, there is no such thing as
3:48what? Everything you're talking about,
3:51for me, I only know one thing.
3:54I know that everything I have, every
3:57element, and everything that exists in
3:59the world, in nature, and in everything
4:02else, consists of four basic things.
4:05These four basic things vary in their
4:08proportions. What are these four things
4:11?
4:12He said fire, water, air, and the fourth
4:14one—what he considered to be earth, like
4:17clay, for instance.
4:19It’s like the movie Avatar; to him, the
4:22whole world is just these four things.
4:25So he said, looking at what you're
4:28saying, for example, I have iron.
4:30He said, look, its proportion might be
4:3330%fire, 20%water, and 25%and 25%.
4:37He said that's its composition, like
4:39throwing them in a blender to get it.
4:42He said, okay, and for something like,
4:45say, gold, for me it would be something
4:48like—he said increase the fire a bit,
4:50make it 40%, and keep the water at 27%,
4:53and for this earth part, make it 20%.
4:57He said, that's how much? 20, 20, 40,
4:59and 40 is 80. He said you have 20 more—
5:02so those are the proportions for
5:05creating gold. So, for Aristotle,
5:08everything was just about changing the
5:10ratios of these things.
5:13Consequently, he ignored everything
5:15Democritus had said before him, claiming
5:18that the composition of elements comes
5:20from these.
5:23If I tried to break them down, I
5:25wouldn't find fire burning me, water
5:27drowning me, or anything like that
5:29happening.
5:31That was his assumption. He said, well,
5:34is this actually correct?
5:37We said, well, that's nonsense—we don't
5:39live in the movie Avatar for that to be
5:41true.
5:42So what happened? Because of what
5:45Aristotle said, imagine you have a ton
5:48of iron, bought as scrap from the guy
5:51calling out under your house.
5:54So I got a ton of iron, went into the
5:56kitchen, and said to Mom, "Mom, make me
5:59some gold at home right now."
6:01She'd say, "Okay, come on, let's add a
6:04bit more..." Of this fire, to make it 40
6:06instead of 30, meaning we keep heating
6:09it over the fire, and we want to...
6:11Reduce the...Earth, so we clean it, and
6:13reduce the air, so...We keep it away
6:15from the air.
6:17And we keep doing all of that.
6:19Then I'll find that...Mom made gold at
6:22home, and I found that...All the
6:24scientists at that time and in that era
6:26were interested in turning cheap things
6:29, cheap metals, into...Expensive things
6:31, like...Like what?
6:33Gold and...Silver. I mean, they kept
6:35taking...Iron, and saying, "I'm not
6:37leaving today, or...""I won't die until
6:38...""Until I turn you into..." Something
6:40expensive. Why? So that scientists can
6:43benefit, after all, everyone wants money
6:44. So what does he tell me? He tells me
6:46that because of Aristotle, science as a
6:47whole was delayed, and chemistry was
6:49delayed significantly.
6:50So, was Aristotle right? No. We then
6:52came to what? In the 1800s, we found a
6:55scientist named Dalton. So we have
6:57Democritus, who was the first, then
7:00Aristotle, then Dalton. Dalton was a guy
7:02who, well, he had a deep perspective,
7:05and he was the first to say something
7:07logical about what? About our chemistry
7:09and the composition of the atom.
7:12What did this Dalton guy tell me? He
7:13told me that Democritus was right.
7:16That, for me, this atom is what?
7:19It is, so the first thing he said was
7:21that it is what?
7:23That it cannot be broken and that it is
7:26called, also for him, so this is the
7:28first thing said by who?
7:30The first thing said by the guy named
7:32what? Named Dalton. So Dalton will tell
7:34me many things now, or he knew now what
7:37?
7:37The first thing being that the atom, for
7:39me, cannot be broken, this is what? What
7:41Dalton said. And what else did Dalton
7:43tell me? He told me, look, what is this
7:47atom? It is
7:49Or it is the smallest thing through
7:51which I can say that this is the
7:53composition of what? That this is my
7:55composition of whatever is in front of
7:57me, meaning what?
7:59That I have, right now, the whole world
8:01consists of what? Of whatever is around
8:04us, we believe it consists of what? Of,
8:07so this is what we? Know. So now, if I
8:10have everything, it consists of what? Of
8:12, he asked, are they all the same? He
8:14told me no, they are not all the same.
8:16He told me a specific thing. He said
8:17that the atoms of, for example, iron—
8:20here are the iron atoms, Fe, that is its
8:22element—I say to him what? And it's
8:25different now from the other atoms of
8:27who? Of Ag, which is what? Which is
8:29silver.
8:30He told me, I have now the atoms of iron
8:33, they are all what? They are, meaning
8:36what? Meaning they are the same. So the
8:39atoms of iron are, let me just shrink
8:41this pen a little.
8:44The atoms of iron are, he said, what
8:45about the silver atoms, what are they
8:47like?
8:48He told me that the silver ones are also
8:49what? They are [the same] among
8:52themselves.
8:54So now, these two, they are the same,
8:56they are identical.
8:59He said, so since they are the same now
9:01, what does that mean? Are the iron ones
9:03the same as the silver ones? He told me
9:05no. He said that what? That
9:09Are the same.
9:11But they are different from each other.
9:14Meaning now, like iron, they are all
9:16what? They are the same, but the silver
9:18ones, on their own, are also the same,
9:21but the silver and the atom, is this
9:23atom like this atom? He told me no, they
9:26are different from each other, but all
9:27of these are the same, and all what? And
9:29all of these are the same. So, this is
9:31the second thing who told me? Dalton
9:33told me. Logical talk.
9:35He said, "Okay, now for me, what else do
9:37I want to know?"
9:39He told me the third thing is for you to
9:42tell me that when I make a compound, he
9:44said, what is this compound like?
9:48He said it's something like, for example
9:50, water or carbon dioxide.
9:53He asked, "What happens?"
9:55He said that I take one of them and put
9:59it on another of another, meaning for
10:02water, for example, I'll take two
10:05hydrogens and attach them to one what?
10:09The oxygen, which is the what? The
10:10shaded one. He said it would be likewise
10:13.
10:14He said I'll take two of the shaded
10:16oxygens and put them on what? On one
10:19that is what? The one with these two
10:21lines.
10:22So now, for me, what does it consist of
10:25?
10:25It consists of, meaning I bring a
10:28collection and keep collecting for
10:30myself.
10:32Of what?
10:38Now for me, what are they?
10:41Meaning for me, from different what.
10:44Okay, so this is what for me, the what?
10:47The talk he's saying.
10:50And that they are for me, and that they
10:53are where for me?
10:55In the same, but if I have now for me
10:58this different, then it will be what? It
11:01will be what for me?
11:03Their what are different from each other
11:04, but as long as I am within the same,
11:06they will remain what?
11:07The same, and there is no problem
11:09between them.
11:13So now, this is the talk of what? Of
11:15Dalton. Did he tell me anything else?
11:17What did he say?
11:19That what you told me now, that I have
11:22this word implies two things, he said
11:25first thing that means all for me
11:27consist for me of what?
11:31All consist of, and these what are they
11:35?
11:36What does it mean? It means they cannot
11:38be broken; I cannot make them, nor can I
11:42what? Break them.
11:44So, neither can I make them, nor can I
11:46what? Break them. So neither this nor
11:49that, I cannot make them nor break them
11:51.
11:52So this is the talk he said, so let's go
11:53back, what did he say? He said that it
11:56is, well, he said it consists of four
11:59things and I keep changing their ratios
12:01.
12:02What did Dalton say?
12:04He said that this is the smallest thing
12:07I have, that it cannot be broken or made
12:10, that all consist of, and that those
12:12from the same are alike, and those that
12:15are different are different from each
12:18other, and that it is what?
12:21It is, meaning collections of what?
12:26Okay? Great, beautiful. Okay, let's go
12:29down, and he told me, word for word what
12:32he said to me, let me take it and break
12:34it down. What did he say?
12:37He said, for example, let's take like
12:39the, here is the, I don't know, the
12:42mouse has something strange, you know,
12:44where does this come from?
12:49It comes from me taking two, for example
12:51, and saying here are two of the, and I
12:53put them with what?
12:55With one of the, so it starts to produce
12:57what for me?
12:58Here is what, exactly?
13:02This, for example, is my composition of
13:03what? Of water. Okay, so I say to him
13:05what? I mean, is this balanced? I have
13:07nothing to do with weight; I am not
13:08talking about weight, I am talking about
13:09what?
13:11That I needed how much, compared to how
13:13much I needed of hydrogen versus how
13:14much of oxygen, so now what?
13:17Two to one. Well, now I want to know.
13:21I mean, generally, what will water look
13:23like? Generally, what does "generally"
13:25mean? I mean, will it always be, won't
13:27there ever be a time, for example, where
13:29I find it what? I mean, it said to me no
13:31, I want to be, for example, it said to
13:34me I want to be what?
13:37It said to me what? It said to me no,
13:39the one who told me what happens, will
13:41it remain or not? It told me about a
13:43scientist named what?
13:45Named Proust, or this or that, or
13:46whatever the pronunciation of his name
13:49is, or what it was like back then, he
13:51said I have something called...
13:55What is the...
13:58He told me, sir, now that I have every
14:01compound that exists for me, it has
14:04fixed ratios, meaning fixed, the ratios
14:07, so now I have what?
14:10Fixed ratios. These fixed ratios now, to
14:13me, are like what?
14:15He told me now.
14:18He told me if you went right, left,
14:20walked into the future, or returned to
14:22the past, you will always find that
14:24water is formed by taking two of
14:26hydrogen and one of oxygen.
14:29He said great, he said well now, he said
14:31that the fixed ratio I have is two to
14:34one, which is the most simplified thing
14:36.
14:37He said, well now, for me, if you told
14:39me I currently have 20 of hydrogen, how
14:42many oxygen would I have in terms of
14:44count?
14:47So, will I just be guessing things I
14:50don't know?
14:52He said no, you can easily figure them
14:54out by doing a cross-multiplication,
14:57like what we learned in middle school.
15:01I have a ratio between two numbers here
15:04, and the number below represents the
15:06same thing, so the ratio stays constant
15:09.
15:11Since the ratio stays constant, if it
15:14was two to one, then when I make this 20
15:16, how much will this be?
15:19It will be 10. When I make this 20, this
15:22will be 10. So for me, there is a
15:24constant ratio.
15:26He said, what about something else? Take
15:30, for example, the NH3, which is ammonia
15:33.
15:34In this view, my ratio is fixed: one N
15:36to three H. That is the constant ratio.
15:40He said, if I have 15 N, how much H
15:43would there be?
15:45Just do a cross-multiplication and say
15:48it will be 15 times 3 divided by 1,
15:50meaning how many H must be present to
15:53bond with 15 N and produce NH3.
15:57Okay, so this is what we call "definite
15:59proportions," which means I have
16:02constant ratios.
16:04Are these constant ratios between what
16:07we just took—the number of atoms?
16:10He said, well, it might come up in an
16:13exam or a problem and ask for mass, not
16:16the number of atoms.
16:18I'd say, fine, tell me the weight of H2O
16:21. What is the weight of one H and one O
16:24?
16:26He said, so you can now say that for
16:29every, for example, from the hydrogen I
16:32have, I take what?
16:35The hydrogen, I'm talking to you here
16:37now, this two, as hydrogen in general,
16:40how much oxygen will I need in contrast
16:42? I will need grams.
16:45So, if he says he wants it in grams, by
16:47weight, I will say I have every two
16:49opposite to it is what?
16:51Opposite to it—and these numbers, he
16:53will provide them, don't worry, they
16:54won't be missing.
16:56So now, two, I have what opposite to it
16:58?
16:59So, I tell him, okay, if you set the
17:01weight for me now, and you tell me I
17:03have now, how much oxygen will
17:05correspond to it for me?
17:07You just do the same
17:08cross-multiplication now and say...
17:13Or say, the two was multiplied by what?
17:16It resulted in, so I will also multiply
17:18the, so it will be how much?
17:20He said,
17:22of oxygen is what is needed.
17:24So this is what?
17:28It means I have constant ratios for
17:29every, so no matter if he says I have a
17:32million of this, I will see how much of
17:34the other thing I have that this million
17:36will need in return.
17:38From the other one I have.
17:40Beautiful, beautiful.
17:42Alright, what came next after we
17:44understood the story of the and we
17:45reached the point where Dalton told us
17:47that
17:53they are different from each other and
17:55that the is made of what? By gathering a
17:58few things. Is this the latest we've
18:00reached in terms of?
18:02No, he told me why?
18:04Because in Dalton's view, his model is
18:07that for me, the is a solid sphere, as
18:09he said, meaning a solid ball that
18:12cannot be divided, and I don't know its
18:14contents or the on it, or anything.
18:18So where did this image we have come
18:20from? That I have something in the
18:22middle and things revolving around it?
18:24He told me, take it step by step, let's
18:26look at, he said what? There was a
18:28scientist named what? His name is
18:29Thomson, and this scientist named
18:31Thomson told me what?
18:33He is a guy, the one in front of me, a
18:35sharp, great guy.
18:38He said, "I discovered while I was
18:40experimenting, doing an experiment
18:41called the cathode ray tube," meaning I
18:44have something called a cathode ray.
18:47He said, what are these cathode rays?
18:50He said it's a charge with a certain
18:52light that emits in a tube.
18:56This tube is connected to a high-voltage
18:59power supply, meaning it has a lot of
19:01electricity, very, very high electricity
19:04, and at the same time, the pressure
19:07inside the tube is very, very low, or
19:10for me, what is the pressure right now?
19:14Low pressure, and the pressure is very,
19:16very low. It's low, so it's considered
19:19evacuated, as if there is nothing inside
19:21. So the pressure is low and my
19:23electricity is high.
19:25He said when I pass it through this part
19:27, a ray comes out of it.
19:29He said the ray that comes out is called
19:31a cathode ray. So the ray that comes out
19:34is called what? It's called a cathode
19:36ray.
19:37He said in the middle of his experiment
19:39, he thought, "Why don't we, Thomson, do
19:41something?"
19:43Let's take a positive plate and put it
19:46up here, that is the positive plate on
19:48top, and he said, "Why don't we also get
19:50a negative plate and put it on the
19:52bottom?"
19:53He said something with a positive sign
19:56on top and a negative sign on the bottom
19:58.
19:59He said the line usually travels in a
20:02straight line like this, but he said as
20:04soon as I brought the positive and
20:06negative plates, I found that it didn't
20:08travel in a straight line.
20:10He said, so what happened?
20:13He said I found that the line I had, I
20:15found that it went up towards the
20:17positive plate and moved away from the
20:19negative one below.
20:21Let's recall a simple thing for us now
20:23in physics or electricity or anything in
20:25general. What were we saying?
20:28We were saying that like charges, sorry
20:31, opposite charges start to attract each
20:35other, and like charges repel each other
20:38.
20:40So now, if I have something and I bring
20:43it close to something else, what will
20:46happen?
20:48It will happen that each one will return
20:51in the direction it came from, so they
20:53will go back like this.
20:56He said, well, if I brought one and one
20:59, what would they do?
21:03But if they were different, they would
21:06start to come together, so what would
21:08happen between them?
21:12So now, for me, what is the situation?
21:15What happens to my signals?
21:18The ones that are the same start to
21:19repel, meaning they move away from each
21:21other, and the different ones start to
21:22do what, meaning they are attracted to
21:24what?
21:25To each other.
21:26Alright, so what did he say now?
21:29I said to him, well, in this case, when
21:32I found that the line I had moved up and
21:36away and then closer, what does that
21:39mean?
21:41This means that, so now this cathode ray
21:43has proven that it is what?
21:46That it has what inside it, a signal,
21:49what is inside it?
21:51What kind of signal? A signal.
21:54Well, now for me, if this cathode ray is
21:58what?
22:00That here there is a group that, when I
22:02connected it to electricity, I knew that
22:05when I connect it to electricity, I find
22:07something coming out of it.
22:09Is the thing coming out of it, now if I
22:12brought a natural one before it enters
22:14what?
22:15In this device, I brought this atom now
22:18, I put it here, I put it here, what
22:21will I find? Will it be attracted to
22:23either of them?
22:24He said what? He said no, it won't be
22:27attracted. So now I am sure and certain
22:30that my natural atom...
22:34My natural atom is neither this nor that
22:37, so what is my natural atom?
22:40It is neither positive nor negative.
22:44He said, well, what came out of the atom
22:47is something from the atom.
22:50He said the thing that came out of the
22:52atom, how was it attracted?
22:55It must be like it. He said no, so I
22:58have inside the atom two things:
23:01something that came out here and the
23:04rest.
23:05So now the thing that came out and the
23:08rest, he said my drawing that I formed
23:10of the atom is the one down on the right
23:13, which is what?
23:15That I have a large cloud.
23:21This large cloud, I have a large cloud
23:23and swimming inside it now for me is
23:25what?
23:27Things, and what did I call these?
23:30I named them, so the things I have, what
23:33did I call them?
23:36So the things, what did I call them?
23:39So that's great and perfect. I knew that
23:42for me, from, so he told me what?
23:45He told me that he made me aware that I
23:48have something called, whose charge is
23:50what?
23:51Negative.
23:53So he told me that the thing I have, he
23:54said I represented this example with the
23:56example of what?
23:59Or as if it were a piece of, or I
24:01represented it with another example,
24:03which is the watermelon. The watermelon
24:05now for me consists of what?
24:08It consists of the peel I have here,
24:10forget the peel, the important thing is
24:12that inside I have the whole watermelon
24:13, which is the red part, here is the red
24:15watermelon for me, and inside it is what
24:17?
24:19Inside it are the seeds, so here is what
24:21? Here are the seeds for me. He told me
24:24, why did I call this view the
24:26watermelon?
24:27He said it's because the red part, which
24:30is the watermelon, represents the
24:32positive, but the seeds inside are what
24:35?
24:36They are the electrons, which are what?
24:39Which means, let’s go back again.
24:42What did he say I have? I kept breaking
24:45things down until I reached something
24:47called an atom that can’t be broken
24:49further. Then Aristotle said everything
24:52is composed of four basic elements:
24:53water, fire, earth, and air. What did
24:55Dalton tell me? He told me that now I
24:57have an atom, which is what? Something
25:00that cannot be broken, created, or
25:02destroyed, and that all matter is made
25:05of atoms. He said atoms of the same
25:08element are identical, while those of
25:11different elements are different. Also,
25:14he said a compound is what?
25:17It is a collection of different elements
25:19, and we learned there are fixed ratios
25:22for every compound.
25:24Thomson taught me what? That I have
25:27something present for me, which is what
25:29? That its charge is what? It is
25:31negative. So, that is what? Thomson. Did
25:35Thomson tell me the weight of this
25:38electron or the specific charge value?
25:42No, I only know it's negative, but do I
25:44know the weight or the mass of this
25:47electron?
25:48He said no. He said, who then told me?
25:51He said there is a guy named Millikan,
25:52the cleanest scientist among them, his
25:53picture is so sweet, he said what?
25:56He said I conducted an experiment, I got
25:58some oil, and I exposed this oil to
26:00X-rays, so it would drop down for me.
26:03He said these are naturally falling, and
26:06I expose them to what?
26:10So they move up and down or fall at a
26:12certain speed, and from that, I knew...
26:16The charge and mass of what? The
26:19electron.
26:20Am I required now to know how this
26:23device works or its details?
26:25Not at all. But what am I required to
26:28know?
26:30To know that I have a scientist named
26:31Millikan who did what?
26:33This Millikan said what?
26:36He said that I was able to determine the
26:38...Charge and mass of the electron
26:41through what?
26:43Through what is it called?
26:45He used oil in it.
26:47Okay?
26:48So now, where did I know this from? From
26:53the...From the oil through what? Do I
26:55need to know anything else about this
26:57point? Not at all. Okay, what about me
26:59now? I moved on to another scientist, a
27:02scientist named Rutherford, and he is
27:04one of the people who led me to the...
27:06View of the atom we saw at the very
27:08beginning.
27:09He said this is what?
27:11This is a great scientist who had two
27:13students, one named what?
27:15And one named Hans, or two students who
27:18were with him.
27:19He said these two students were
27:21conducting experiments.
27:23He said what?
27:24I got something called alpha particles;
27:27we will take it at the end of the...But
27:29I need to know what it consists of? What
27:32does it consist of? Just a thing, it’s
27:36just something like that.
27:38So what thing?
27:41He told me this thing I'm emitting many
27:44alpha particles from, which is this
27:46thick red line, he said this alpha,
27:48which for me now, what did I do?
27:53He said I placed a very thin sheet of
27:56gold, so I placed it and surrounded it
27:59with a substance that will shine; this
28:02substance will shine so, it’s covered
28:05with—well, these details don’t matter,
28:08but I’ve covered it with something shiny
28:12so when something hits it, I see what it
28:15did?
28:16Do you see the glow here? It created
28:18this appearance.
28:20Great.
28:22Well, he told me, sir, what was he
28:24expecting to happen?
28:28Isn't the last thing we reached now that
28:31the atom is what it is, so what now?
28:35I have it here as if it is what? As if
28:37it is a circle here for me, looking like
28:39this.
28:44So for the circle that looks like this,
28:46what should I tell him?
28:48I should tell him, well, I’m supposed to
28:51have one of two things: either when I
28:54pass these alpha particles through, they
28:57all go through just as they came in the
29:00same number, or they hit something and
29:03return...To where they came from.
29:07You are now kicking a ball, here is the
29:09ball which is the red line now, you
29:11kicked it and what?
29:13The part in front of you is blocked.
29:15So you kick it into the wall and it will
29:16what? It will bounce back at your face.
29:17He said, or now what?
29:20That this is not a wall and it’s like
29:21platform nine and three-quarters, and
29:23you will pass through it normally like
29:25Harry Potter, and there is no problem,
29:27as if this place is what?
29:28Meaning what, an illusion? There are
29:30many empty spaces present. He said what
29:32? He said what happened was neither this
29:33nor that. He said what happened is what
29:35? He said what happened is this, that,
29:36and something else too. He said what? He
29:39said I found, well, that I have things
29:41that passed naturally, meaning they
29:43passed normally. Meaning the things now
29:46for me, these lines, passed normally.
29:49Great, so I have things that passed
29:51normally.
29:53So as long as they passed normally,
29:55there is—so the first thing, since they
29:58passed normally, is that there is empty
30:00space for me within the gold foil,
30:02meaning inside this gold foil there is
30:04what passed normally.
30:07He said, okay, he said I also have
30:09something.
30:10He said I have things here as if they
30:12hit the wall and bounced back, but
30:13didn’t bounce back at his face—rather
30:14they bounced off far away, and there are
30:16things you will find bounced back at his
30:17face normally, but for me, there are
30:18things that bounced back.
30:20So there are things that are deflected.
30:22So now for me, what? It's like this.
30:26So I have things here that are what?
30:29I have things here that are what?
30:30Meaning they were reflected. He told me
30:32there are things that passed through,
30:34but instead of moving in a natural
30:35straight line, he said they deflected
30:37sharply. He said deflected sharply,
30:39meaning those two lines there, he said
30:41what deflected sharply is what I call
30:43what? He said it deflected; this
30:45deflection to me in English means what
30:47did it do? It scattered, so I have
30:49things that happened to them, which is
30:50that they...
30:55This means it didn't just return to how
30:57it was; rather, it deviated slightly
30:59from the natural path it was supposed to
31:01take.
31:03He said, "Why do I have something that
31:05deviates, and why is there something
31:08that..." Since we said that this
31:10represents for me that it is empty space
31:12, as long as it passed through—sorry,
31:15the empty space that I am pointing to,
31:17which is number one, that is what?
31:20It's normal, so it passed through
31:23naturally.
31:24And this means that it hit something, so
31:27as long as there is something in the
31:29middle here, for me, it hit something to
31:31cause that.
31:33But what deviated, he said, "I was
31:35walking normally like this and then did
31:37this."
31:39That means I didn't hit something, but I
31:42was walking here, entered a street I was
31:44walking in normally, found dogs sitting
31:46there in this area, so I turned and
31:48walked in a different street.
31:51But did I go back where I came from?
31:54No, if I went back where I came from,
31:56they would chase me, so I walked to the
31:59side.
32:00He said, "Okay, the scene that
32:02represents the formation of the atom or
32:05the atomic model that explains this view
32:07," he said to me, "Look, as long as you
32:10were walking normally and hit something
32:13and returned, this means there is
32:15something here for you." So for me,
32:18there is something here. Great, so there
32:21is something now for me.
32:23He said, "Now this is the first thing,
32:25that I hit something, and you were
32:27walking normally and passed through
32:30without any problem, so there is also
32:32empty space here."
32:34So there is the empty space that exists
32:37, and he said you were walking normally
32:39too and then you deflected.
32:42Who does this scene remind me of? Yeah,
32:44what does this remind me of? Of the
32:46Thomson model.
32:48Wasn't Thomson moving normally and
32:49started to deflect? He told me, when did
32:51he deflect? When he was near the
32:53positive charge or when he was
32:55approaching a positive charge.
32:58But here, I don't have a positive charge
33:00that he approached; he just deflected.
33:03So, for me now, as long as he deflected
33:05, I have repulsion.
33:07We said that this happens between what?
33:09Between charges that are the same. So,
33:12what is the charge he is entering with?
33:15It is positive, so I am coming like this
33:17, and this means the solid part in the
33:20middle, what is it?
33:22It is also positive.
33:24So, I have now reached three things,
33:26what are they?
33:28First, that I have this gold foil is
33:30made of what?
33:32Of atoms, but what about these gold
33:34atoms?
33:36He told me that gold looks like this,
33:38with something solid in the middle.
33:41So, what is its charge for me? Or what
33:44are the particles inside it?
33:47It means that at the same time, I have
33:50empty space around these particles; this
33:53means for me, there is space around the
33:56middle particles, and because all of
33:59this together is what?
34:02It is the atom.
34:04So, I learned that the atom has a part
34:06that made things bounce back, a space
34:07that let them pass through, and a part
34:09that made them deflect.
34:12Understood?
34:13So, this is the model where I learned
34:15what the atom looks like. He said, "But
34:17Thomson told you a while ago that there
34:20are electrons, so where are they here?"
34:22He said, here it’s the opposite.
34:25Didn't Thomson say I have a positive
34:27sphere with negative electrons inside?
34:29He said, "Here we reverse it. What will
34:32you say?"
34:33That I have a nucleus here, so it is the
34:37atom, right?
34:39Because this atom as a whole, what is it
34:41?
34:42It is completely neutral overall, it has
34:45no charge.
34:48Therefore, I have a positive nucleus in
34:51the center, and he called it a proton,
34:54and he told me that in order for the
34:57atom to be neutral, I have electrons
35:00revolving around these protons, and he
35:04called this the electron cloud.
35:08So, let’s review simply: I have them all
35:12in front of me, ignore the last two
35:15since they aren't for us now.
35:19Dalton said that an atom is an
35:21indivisible sphere, it's made of
35:24combinations, and atoms of the same
35:27element have the same structure, while
35:30different elements have different atoms
35:33.
35:36We then moved to Thomson, who suggested
35:39that as it moved, it started to deflect
35:42when it neared the positive, so he
35:45determined there were electrons, and
35:48these electrons float in a cloud of
35:51positive charge.
35:55Then came Rutherford, who said for me,
35:57there is a nucleus in the middle.
36:01When I took alpha particles, which are
36:04positively charged, some passed through
36:08, some bounced back, and some deflected
36:12.
36:12So, this is the theory that there is a
36:15nucleus with electrons revolving around
36:18it.
36:22Okay, so this is what the scientists
36:24said about its composition.
36:27Is this important?
36:30Yes, because we can get questions about
36:32it.
36:34I want to know these three names:
36:36Thomson now looks like a watermelon.
36:40Thomson is like a watermelon, and
36:43Rutherford is what?
36:46He is a scientist, right? That's what
36:47he's called, a scientist.
36:50Something chic and elegant, what did it
36:52say? That for me, what did it say
36:53regarding...? Regarding the fact that I
36:56now have things that are what?
36:59They have something in the middle and
37:01around it, okay.
37:03So what is that?
37:08How did the atom reach our current stage
37:10?
37:11The atom reached the stage we see now,
37:13where I have something in the middle,
37:15what is it? What is its deal?
37:18And I will call it what? This is the one
37:19that has, so what is this composed of?
37:23That exists for me and those orbiting
37:25around it, okay.
37:28So, so far, this is great, very, very
37:30great.
37:31So, we learned what? The formation, the
37:34journey of the formation of what? The
37:35atom in the current shape we have. It
37:37said yes, so let's look at a question,
37:39what does it say?
37:43We will leave this question until after
37:44we move forward so that what?
37:46So that we can get it right. It said,
37:48now you've defined the atom for me, you
37:51told me it is what? It consists of
37:53something in the middle with things
37:54orbiting around it. What is this?
37:57It said, remember from what we took in
37:59middle school that I have something made
38:00of what?
38:02And orbiting around it, what is this,
38:05what is its deal? What does this contain
38:07?
38:08It said it has two things; it has the
38:10blue ones with their sign like that, and
38:12those with no sign, the ones colored—I
38:15don't know what that color is called.
38:18It said, what are these called?
38:20They are called—so let's remember that I
38:23have plus the inside, and the orbiting
38:26around them outside.
38:29Now, if I want to make a comparison
38:31between them, it said, look, the proton
38:33, its sign is what?
38:35Or its charge is what?
38:38It is...then the electron is...then the
38:40neutron, it said it is...so even though
38:43it's not just protons, which are
38:45positive, it also has neutrons, but
38:48since these neutrons are neutral, then
38:50neutral and positive means the whole
38:53nucleus for me is considered what?
38:57Considered to be positive.
38:59Alright, it said next, as for weight,
39:02how is it for me? It said in terms of
39:04weight, the weight of the proton is the
39:06same as the neutron, meaning this is one
39:08and this is one. Is the weight of the
39:10electron very, very, very small to the
39:12degree that we say it is—that I can
39:13ignore it for my purposes—is it what? 1
39:15/2000th of the normal weight of the what
39:18? The proton and the what? And the
39:20neutron. I don't want you to memorize
39:22what? What that normal weight is exactly
39:24, but I want you to know for yourself
39:26that what?
39:27That it is 1/2000th, meaning...
39:33Much smaller than the weight of what? Of
39:35the proton and the what?
39:37And the neutron, this is the composition
39:39of what? Of the what? Of the natural
39:41atom I have.
39:43Okay, the composition of the natural
39:44atom here, when it asks me and says I
39:46have this, and they all have electrons,
39:48protons, and neutrons, and match them
39:49for me. So we will do some matching like
39:51in primary school: is this electron
39:53positive, no charge, or negative? It
39:54said this electron is what? This is
39:56negative, so what about the protons? He
39:58told me protons are positive. He said, "
40:00What about the neutrons?" He said, "
40:02What do neutrons have?"
40:04What is this, then? Is it just me
40:06connecting things, and did I do anything
40:07other than connecting? He said, "No, you
40:09didn't do anything but connect."
40:11Alright, there's a session uploading now
40:13, let's look at it. It's uploading, okay
40:15, we'll see when it finishes halfway. So
40:17, what is he saying here?
40:19That I have this, which is what? This
40:21easy, simple connection.
40:24He said, "Alright, now when I talk, he
40:26tells me to do something nice, Doctor."
40:29So I tell you what? What is the nice
40:31thing we can do now? He said we'll take
40:34it and try to see what their
40:36distribution looks like.
40:38The distribution isn't the electron
40:39distribution we learned before in middle
40:41school; no, he said I want to know how
40:42many protons and how many neutrons it
40:43has. He said, "How do I know that?" He
40:45said, "Now I will bring you what?" A
40:47picture now of what? Of the...
40:53Let's pause here and get a picture of
40:55...
40:58Let's go back and recall together what I
41:00used to say about the numbers placed on
41:02the element of the...He said I have two
41:04important numbers.
41:06The first number is the one at the top.
41:09Which is the number at the bottom, the
41:12atomic number.
41:13Now, what does this express for me? The
41:15atomic number is what expresses for me
41:17...
41:20The number of protons present for me.
41:23Which are what? Which are inside. The
41:25nucleus, like that. This nucleus has six
41:26inside it.
41:28He said, at the same time, this atomic
41:30number equals for me the...Number of the
41:32...of the electrons.
41:34The number of electrons I have in the
41:35normal state of the...of the atom.
41:38Now, the number at the top is the mass
41:39number. Which is equal to what for me?
41:41It is equal to the number of...the...
41:43The number that is the thing inside...
41:45inside the nucleus.
41:46So the mass number expresses for me what
41:48is inside the nucleus. What is inside
41:50this nucleus? Inside it are protons plus
41:53...plus neutrons. So now, if I told you
41:55about the carbon in front of you, tell
41:58me how many electrons and how many...I
42:00mean, how many—here's an electron. Look
42:02, let's always get used to doing it like
42:04this for the electron. Here's an
42:05electron, here's a proton, and here is a
42:08...here is the neutron. Okay. I want you
42:12to tell me now how many electrons,
42:13protons, and neutrons are in carbon. And
42:15the cobalt on the other side, what...
42:16how many electrons, protons, and
42:18neutrons does it have? So I tell you,
42:20here is carbon. The electron is the
42:21atomic number, so I say six. How many
42:23protons? It will be...six. So how do I
42:25find the neutron on its own? I will say
42:27to him, didn't you tell me that the mass
42:29number equals the proton plus the...
42:31neutron? So the neutron will equal what
42:33? It will equal the mass number minus
42:35what, minus the proton. So here we have
42:37what, 12 minus six, which means how much
42:39, it means six.
42:41That is the number of neutrons inside
42:43the atom of carbon, which is this one.
42:45Now, what about cobalt? It told me 27 is
42:47the atomic number. So these electrons
42:49will be how many? 27 as well. And the
42:51protons will be how many? 27 as well. So
42:54for the number of neutrons, I'll say
42:56fine, so let's subtract how many?
43:00This one, I will find that it comes out
43:01to be how much? I will find that it
43:03comes out to be how much?
43:07So now this is the number of neutrons
43:08available to me, so the number of
43:10neutrons doesn't necessarily have to
43:11equal the number of protons; it might
43:13differ, and you'll find that most of the
43:14time it is different.
43:17So for me, I should know how to find the
43:20number of protons, neutrons, and
43:22electrons just from the mass number and
43:25atomic number in front of me.
43:28Well, it tells me, do you remember that
43:32you have, I mean we will do something
43:34now between, or before we proceed, we
43:37will talk about a simple point and then
43:40move into it.
43:43What is the simple point we will talk
43:45about now?
43:46It says, do you remember, didn't you
43:48learn in middle school that I have
43:50things called what?
43:51They are called ions. It said yes, and
43:53said, what were these ions exactly? They
43:55are, they either lose or gain what?
44:04It said, well, what exactly happens? It
44:06said you have something like sodium. It
44:09said this sodium will do...
44:15So that it becomes, and it will get an
44:17electron to become, how did we do it?
44:20How did we used to do it in middle
44:21school? We say that I have here...
44:25Distribute them into K, L, and M. I say
44:27two, then eight, then one. It is
44:30important for me that I have eight in
44:31the last one. So I will remove this one
44:33completely, and I will deal with this
44:34electron.
44:35If you don't remember, that's fine, you
44:37don't need that right now.
44:40Okay, I have here, look, I'm going to
44:43erase it anyway, so you tell me now, how
44:46many electrons, how many protons, and
44:49how many neutrons does it have?
44:53Well, I will tell you, for you now, what
44:56was the sodium originally?
44:59It was 11 on the bottom and 23 on the
45:01top.
45:02So you tell me, now that it has lost [
45:03an electron], what did it become? It
45:05became called Na +, so it lost an
45:07electron.
45:08So you come and tell me, what will its [
45:10number] be? I tell you, what was it
45:13normally? It was 11 and it lost how many
45:15? One, so it became how much? It became
45:1810. The protons will be the same and
45:20won't change. Will it change? It's 11.
45:23The neutrons will be how many? It will
45:25be the mass number on top, which is what
45:28? Minus 11, I will find it comes out to
45:29be how much?
45:32It said, well, I have something now like
45:33what? Like oxygen.
45:35This oxygen will do...
45:39In order to transform and become for me
45:41, how much? It transforms and becomes 2
45:44for me.
45:45So, what were the numbers for this
45:47oxygen originally like?
45:49How many were at the bottom for me?
45:51Eight at the bottom, and how many at the
45:53top? 16 at the top. Okay, eight at the
45:55bottom and 16 at the top, so you tell me
45:58this is what it was.
46:00Right?
46:01I say to you now, here is oxygen, it had
46:05how many?
46:07It was eight and it gained two, so eight
46:10plus two is how many?
46:12It became 10. But who stayed the same?
46:17That eight, here it is, eight.
46:20So what about A?
46:23So for it to give me what?
46:26For it to give me how many? Eight.
46:29Right? So you know what it is now. I
46:31don't want you to know anything other
46:34than this information, just the losses,
46:36what happens to the number, the number,
46:38and the number. Do I want to know
46:40anything else? Not at all, not at all,
46:42not at all.
46:43Okay, sir, I understood what you're
46:45saying.
46:46What do you say next?
46:48I tell you that I now have four things.
46:52These four things for me will be what,
46:54what?
46:55They will be
46:58comparisons between elements and each
46:59other using our numbers. And all four
47:01have the word "iso-something" in them.
47:04Look at this, meaning I'll remember it
47:07as things that will be similar to each
47:10other in some ways.
47:13Or things, meaning we can say they are
47:15similar to each other in one thing.
47:18So we know what they are similar to each
47:19other in.
47:20I will tell you now, if I say I have
47:23isotopes, you say, "Isotopes, it has
47:26this 'P' here, do you see it?" You say,
47:30"Yes, it means it has the same number of
47:33..."
47:36Beautiful, the same number of what? So "
47:38iso" is like "same" or like "constant,"
47:40so "iso" means the same thing.
47:43So isotopes, now you say it's fine. Now
47:47, if I told you isobar, good.
47:52For "bar," you say, "Ah, I'll remember
47:56this bar as the number at the top, the
48:00mass number of the element I have here,
48:04which will be equal to the mass number
48:08of the other element."
48:12Meaning you won't move now, just wait.
48:16Well, isotones, good, this has an 'N',
48:19right?
48:20So they are similar in the number of...
48:23so now he told me they are similar in
48:26the number of isotones.
48:29Well, isoelectronic, this is clear, it
48:32doesn't need anything. Then they will be
48:36similar in the...
48:39So now you know why each of these will
48:41be similar in what. Isotopes will be
48:42similar in protons. Isobars will be
48:44similar in the "bar" at the top, which
48:45is the mass number. Isotones will be
48:47similar in neutrons. Isoelectronic will
48:48be similar in electrons. Doctor, you
48:50keep saying things I don't understand.
48:51I'll tell you, let's take them one by
48:53one.
48:54I'll tell you, isotopes, as long as I
48:57have the same number of protons, this
49:01means...
49:04Why, then?
49:05Because I have now
49:09Now I have something constant for
49:12everything.
49:15So here I know that [it] has...what does
49:18it have?
49:20It’s distinct, I will tell you.
49:24What is it?
49:25It’s unique on its own, there isn't any
49:27. There aren't two that are different
49:29from each other. Meaning, there aren't
49:31two different ones, what about them?
49:33Is their [property] the same? Each one
49:35must be different from the other.
49:38So now I will tell you, as long as it’s
49:40like this, what will this be? It will be
49:43the same [one], it will be the same, so
49:45what is the first thing it will be?
49:48Okay, it will be the same, so what will
49:51be different? The number at the bottom
49:53will be the same. For example, carbon,
49:55I’ll find carbon, here’s carbon, here’s
49:57carbon, all three are 6, 6, 6. So what
49:59will be different? The number at the top
50:01, 12, 13, 14. So what was the number at
50:04the top composed of? It is composed of [
50:06plus].
50:07They aren't constant here, in all of
50:09them, it’s six here, six here, and six
50:11here. So who is changing here for me?
50:15So the [protons] are the same. So who is
50:20changing? The [mass]?
50:24It is what changes.
50:26You will tell me, Doctor, does this
50:27really exist? Meaning, is there carbon-
50:2912, carbon-13, and carbon-14? Yes. And
50:31each one exists in certain percentages.
50:33Meaning carbon-12 exists at a rate of
50:3598.9 percent.
50:39Carbon. All the carbon present in the
50:41world, and carbon [14] is present in a
50:43very, very, very small percentage.
50:45So you come and tell me what? You tell
50:48me that I now know that
50:52and what is different is what.
50:54Well, since it is
50:58meaning all those coming up now, you
50:59will find that it is what
51:02What is it? Similar in the bar above.
51:11But the number...below this one is
51:13different, so what is this? I will be
51:15focused. This doesn't mean that as long
51:17as the two [numbers] at the top are the
51:19same, it has the same number of neutrons
51:21. Not at all. They are [protons]...I am
51:23down here.
51:25Plus how much gives me?
51:27Gives me now how much?
51:32So this contains
51:35which is what?
51:36Okay.
51:39The [neutrons] are how many?
51:42How many are in it?
51:43They have a different number.
51:46But the one that is the same is who?
51:50Which is
51:52So this is who?
51:54So the [isotopes] mean?
51:57So now I will calculate, for example.
51:58They aren't clear because they are
51:59written in a small font. Here is
52:01phosphorus, 15 below and 31 above. I
52:04have sulfur here below, and here above.
52:08Calculate the [neutrons] for this one
52:09and that one. I will tell you here, what
52:11is in the?
52:12The P, this phosphorus, what about it?
52:1515 to 31, so how many neutrons does it
52:17have?
52:18And 16 to 32, how many does it also have
52:20?
52:21So when the [protons are] the same,
52:24it will be called
52:30So here is the P, but the neutrons are
52:33what change.
52:35The bar which is what? The bar at the
52:37top which is what?
52:39Beautiful. So the wonderful thing I have
52:43is what?
52:45What should I call this for you? Let me
52:48give you an example now. Now, let's take
52:51the and the.
52:54I looked at both and looked at the.
52:57I told you, what is the? Look here. When
52:59we said the, how many electrons were
53:01there? 10. So the, how many does it have
53:02? It also has 10. And how many does Neon
53:05have?
53:06It also has 10. So they all have, and
53:08those that have the same will be called
53:11what?
53:13So now,
53:16for me, what is it? It is the thing that
53:18has the same
53:25which is what? What is the thing that is
53:27different in it, which is what?
53:31Alright, good, lovely, perfect. Let's
53:34move down, here it tells us
53:41So, Bromine exists in two versions, one
53:47What is this Bromine, then? What does it
53:49have? So you take the Bromine now. For
53:53me to solve this problem, I must have,
53:56so I will get this and get
54:00Let's continue here, and what is he
54:02telling me?
54:03That he wants to know what exactly
54:05Bromine has.
54:07So the number he puts next to this is
54:10what? It is what?
54:15So it is what?
54:16As we agreed now, I know now that it is
54:18Bromine, from the top it has how many?
54:22And from the bottom, how many? Once he
54:24gives me the name, I can get the
54:27Because it will be constant anyway, so I
54:29will go here and say, where is the?
54:31This thing, the Bromine you want to talk
54:33about, what did he tell me? He told me,
54:35here it is, the one I am around, which
54:38is
54:40So, what is the of Bromine? 35. So now I
54:43know it is how much?
54:46It is thirty-35. Alright, 35, now you
54:49tell me, come on, split them yourself
54:52quickly now.
54:54Here is, and here is, and the first
54:57thing they are the same in, which is how
54:59much?
55:00Which is
55:03And how much is?
55:03So it will be how much? It will be
55:08So I will have how many? It will be
56:00Look, for me now, when I talk about them
56:04and say they are similar in what?
56:09He said they are things similar in the
56:12same
56:14So here is what?
56:16Meaning the same, why? Because who works
56:21on this
56:26So who gives me the number of?
56:29Who gives me the? It is the that makes
56:33it, so it is
56:51Meaning its will be different from the?
56:55He said yes, why? Because here, this is
56:59that its above this, meaning I added
57:02three to it, so the three have,
57:05therefore it will be different. He said
57:08yes, different, meaning it won't be the
57:12same.
57:18Meaning the number of protons is
57:19different from the?
57:21No.
57:23So it won't be originally, so this is
57:26wrong.
57:31Meaning it is more abundant than? More
57:34than
57:38I will say to him, honestly look, I
57:39don't know this information, but I look
57:41at the choices.
57:43I agreed that is correct.
57:45Does have correct? No. No, I said is
57:49wrong, so for me, this is also wrong.
57:53Well, what I am sure is correct, for me
57:56this one is out. Is it the first one?
57:59No. So what is it then? Come on, what is
58:02it?
58:04Is there actually anything more than
58:06that, and I tell him this one is correct
58:08? So I don't get stuck and not know what
58:11to do, no.
58:13The answer to the question lies in
58:15understanding the question well.
58:17How do I understand the question? It
58:20told me to read it. It is very obvious.
58:23Read it, read it, I don't know, maybe
58:26it's written wrong. Read it and see what
58:29it wants. Okay, so I say, what is it?
58:31What does it want? What is the thing it
58:34is asking for?
58:36So, what it is asking for, how does it
58:38relate to the information in my head
58:39that I have in the curriculum?
58:41So, what is the law or what do I use to
58:44get this thing?
58:45So this is the first part, which is
58:47understanding the question.
58:50Okay, I understood the question, I start
58:52to analyze the answers and see which of
58:54these answers would be correct and why,
58:55and which would be wrong and why.
58:58I analyze the answers. I might not know
59:00the answer to the question just from my
59:02understanding of it.
59:04Because my understanding of the question
59:05makes me say that, well, one, two, three
59:07, this is what will happen, this is what
59:09will happen, this is what will happen,
59:10but the answers don't have one, two, or
59:12three. So I start to see which of these
59:13answers are logical and which are not.
59:15What exactly does it want from the
59:16answers?
59:18Don't get confused and don't stop. Good
59:20.
59:20This is what? The secret to getting
59:23grades is not to stop. Understand the
59:25questions and analyze the answers.
59:28It tells me here that
59:32I have now
59:36Both have the same, I will say to it
59:39this is 8 18, 9 19, meaning 18 minus 8,
59:41so how many neutrons are here? 10, 19
59:43minus 9, so how many neutrons are here?
59:4510, so they have the same, it told me
59:47yes. Okay.
59:52These isotopes, they are the same, they
59:54are what? The same, so for me what? This
59:58one will be wrong. But these are what?
1:00:00Someone tell me now, what is this?
1:00:01Someone smart, tell me iso what? Isobar
1:00:04. Why isobar? Because the bar at the top
1:00:07, these two numbers are the same.
1:00:09Here O, which means it took two, it told
1:00:12me what?
1:00:13That it has the same of the, I tell it,
1:00:16well, how many are in this?
1:00:18It originally has eight in its natural
1:00:19state and lost two, so it is 10, and
1:00:21this one has how many in its natural
1:00:22state? 10, so it told me, it told me
1:00:24what? It told me, yes, this is correct,
1:00:25and this is called what?
1:00:29Okay, so these two together. And the
1:00:31first one, what was it called? When they
1:00:33have the same, so what?
1:00:38Okay? Beautiful. Great. So what is it?
1:00:41Okay, and well, we talked about ions.
1:00:44Here it says, the calcium, what is in it
1:00:46exactly?
1:00:49So I will tell it now, I don't know, the
1:00:50mouse has something wrong, or the port
1:00:52broke, or there is something wrong,
1:00:53something in the device is lagging, I
1:00:55don't know why.
1:00:57Here it tells me what? This proton, the
1:00:58thing in front of me, I don’t know what
1:01:00it is or what’s in it.
1:01:01So let’s say, come on, let’s take them
1:01:03one by one. First thing, how do we get
1:01:04the protons? From this number directly,
1:01:07so here it is. Now, how do I get the
1:01:09electrons? From the same number, you
1:01:10write it down immediately. No, don't be
1:01:12naive, start by telling me what? Oh,
1:01:13it’s already there, from the [symbol]
1:01:15that exists, what is it? Here it is,
1:01:17this [symbol], what about it?
1:01:20So it did two, so I’ll say here, how
1:01:22much does it become?
1:01:25So how much?
1:01:27Well, the [symbol].
1:01:30For me, it will be how much? It will be
1:01:31the [symbol].
1:01:34So it will be the [symbol], give me how
1:01:37much?
1:01:38So now I know all my numbers.
1:01:43He said, "Oh, right," which is what?
1:01:44Which is the first one.
1:01:46Okay?
1:01:47He tells me [term].
1:01:56The word [term].
1:01:58Means.
1:02:01So what will it do? It will [action].
1:02:05Well, and the word, so it means what
1:02:09will it do now?
1:02:14So I start by saying, he told me, well,
1:02:17this [symbol], did it lose one, two,
1:02:20three, or how many?
1:02:22I don’t know. So what do I start doing?
1:02:24Don't panic, don't sit there saying, "
1:02:25That's it, I can't solve the question,"
1:02:27no.
1:02:28I will get the [symbol] and get the [
1:02:29symbol] and see how the [symbol] will
1:02:31turn out.
1:02:32I’ll get the [symbol], its [value] is
1:02:33how much? I’ll go to the [symbol] and
1:02:35see where this [symbol] is. Oh, where is
1:02:37this [symbol]? It’s right here, the one
1:02:38under the [symbol]. Under the [symbol],
1:02:39here is the [symbol]. Well, the [symbol
1:02:41].
1:02:43Is how much? Is [value], so I will go
1:02:45back here and say, here is the [symbol]
1:02:48, it was up and down.
1:02:51So now, the first thing, the [symbol]
1:02:52will be how much?
1:02:54Well, the [symbol] will be how much? In
1:02:56the same order he wrote it, so you don’t
1:02:58get confused.
1:03:01So that’s how much? So that’s good.
1:03:05And the [symbol], I don’t know.
1:03:07But what I am sure of is that it will be
1:03:09the natural number plus what it will
1:03:11gain.
1:03:13Well, let’s see which of these is
1:03:15compatible with these two, look at the
1:03:17first one.
1:03:19Wrong.
1:03:22This is possible.
1:03:25This is wrong. Here, this makes sense.
1:03:29Here, this [symbol] is carrying the [
1:03:31symbol], so I have either B or D. Well,
1:03:34between B or D, which one is correct?
1:03:37I’ll say, let’s see what the difference
1:03:38is. The difference here and here,
1:03:40someone might catch it and say, "Oh, I
1:03:43increased by one, increased by two, I’ll
1:03:47be more than [value]," so this doesn't
1:03:49work because this is also [value], so it
1:03:52won't be the [symbol], it will be the
1:03:55normal [symbol], but this [symbol] is
1:03:58what? It is what? What he wants.
1:04:03So now, I didn't know [initially], but I
1:04:04analyzed the answers and saw which ones
1:04:06work for me.
1:04:08This is not a trick solution, nor is it
1:04:10guessing or anything; this is the actual
1:04:11way to solve this question.
1:04:13Okay?
1:04:15Perfect.
1:04:17Here he says.
1:04:21Meaning he wants these things to have
1:04:23the same [property], which is called
1:04:24what?
1:04:25Isoelectronic, this is, for me, among
1:04:27the things in front of me, I’ll say,
1:04:28well, what will it be?
1:04:30I’ll take them one by one; you take them
1:04:32one by one and sit there doing them
1:04:33yourself, and I will do what with you?
1:04:35Which one is it?
1:04:37Look, I'll be very generous with you and
1:04:40go through all of them. Right now, what
1:04:42are we doing? We'll get their numbers
1:04:45from the...This one is nine, this is 10
1:04:47, this is 11, this is 12, this is 13,
1:04:49and this is 14 here. This is the...I'm
1:04:52getting their [atomic numbers].
1:04:54This one is eight, this one is 16, and
1:04:57here I have this one, we just said it's
1:05:01how much? Which is how much, exactly?
1:05:04Perfect.
1:05:06Basically, nine, 10, 11, this is the...
1:05:08that represents in this case their...
1:05:10Will they be isoelectronic? No, he told
1:05:13me when would they be isoelectronic? If
1:05:15this one did [a gain] on its own, and
1:05:17this one did what?
1:05:19On its own, then they would all be tens
1:05:21. But here, the Mg, 12, 13, 14, are they
1:05:23? No, when would they be?
1:05:25If this one lost two, this one lost
1:05:27three, and this one lost four, then they
1:05:28would all be how much?
1:05:30They would all be ten. So, A and B are
1:05:31what? Wrong. Oxygen is eight, it will
1:05:33take two, it will become how much? Ten.
1:05:3516 will take two, it will become how
1:05:37much? 18. 34 will take how much, and
1:05:39take two, it will become how much? It
1:05:41remains...So, for me now, are they...?
1:05:44No. Is it possible? It's impossible.
1:05:48I mean, have each one gain 100? No, that
1:05:51won't happen.
1:05:53But the one above, Cl, this Cl normally
1:05:55has how much? It has 17.
1:05:58Argon has 18, and this potassium is how
1:06:01much? 19.
1:06:03When the Cl gains on its own, it will
1:06:06become how much?
1:06:07It will transform and become 18. When
1:06:09this potassium does it on its own, it
1:06:11will transform and become how much? 19,
1:06:13it loses one, it becomes how much?
1:06:1518. They will all be 18. In that case,
1:06:17it is...Correct and accurate, perfectly
1:06:20fine.
1:06:21Okay.
1:06:23Let's move down to...To the...The next
1:06:25question.
1:06:27He tells me...
1:06:31What, what is happening?
1:06:37The board is ten.
1:06:42I mean, the board is probably...
1:06:45The pen was broken and I got a pen.
1:06:48Am I going to get a board now, or what
1:06:50should I do?
1:06:52Thank God, he tells me here...
1:06:56What?
1:06:58Exactly.
1:06:59The...
1:07:06From which of these...
1:07:10How much for me? So I'll start tackling
1:07:12it one by one.
1:07:13He tells me this has 12. Let's assume he
1:07:16didn't even tell me, so I didn't go to
1:07:18...He said "X", something I don't know,
1:07:20it has a neutron and 10 electrons.
1:07:24How do you get all the details? What
1:07:26details do I want to know? I want to
1:07:28know the two numbers, the one above and
1:07:29the one below. He told me the one below
1:07:30represents...
1:07:34But in this case, it did...Say to him, "
1:07:36Man, put it back, man, put it back, it
1:07:38was 10, add one back to it," so it will
1:07:40be 11 from the bottom.
1:07:43Well, and it has 12 neutrons, so above
1:07:45it will be 11 plus 12, so that is how
1:07:46much?
1:07:49I got the two numbers from above, there
1:07:50they are.
1:07:51Did I need anything else? No. Okay.
1:07:53So you come and tell me...
1:07:59So in this case, you need to be sharp;
1:08:02this one is a wrong answer, the one that
1:08:05is highlighted.
1:08:06Why? The atomic number I have is
1:08:09constant, it represents...
1:08:12So it must be 11.
1:08:14It must be 11.
1:08:17Therefore, it cannot be 10, meaning it
1:08:19doesn't change based on how many
1:08:21electrons I lost or gained. If I changed
1:08:23it to 10, it would be something else
1:08:25entirely.
1:08:26So, for me, that's not possible; so what
1:08:27would the atomic number be? 11, well.
1:08:32Which is the one that was solved
1:08:33correctly and is perfect.
1:08:36Okay, it tells me...
1:08:40It wants the mass of the ion.
1:08:42All right.
1:08:43How do we find the mass of this ion?
1:08:45The "u" here is the sum of the protons
1:08:48plus the...plus the neutrons.
1:08:51All right.
1:08:51So, it is the sum of the protons plus
1:08:53the...plus the neutrons. Coming here, it
1:08:54has 13 electrons, 12 protons, and 14
1:08:56what?
1:08:58When it asks me for the mass of the ion
1:08:59, I just add the protons to the neutrons
1:09:00, which is how much? 12 plus the...The
1:09:0214, so how much does that make?
1:09:05And that is how we know the mass of the
1:09:07ion, or mass in general, how we find it
1:09:08. We find it by the number of what? The
1:09:10protons plus the number of what?
1:09:13The neutrons in this manner, when it
1:09:15says how many "u"—because in a little
1:09:17while we will learn about something in
1:09:19grams, and it will be different— "u"
1:09:21means unit, so remember with me that
1:09:22these are units; so 12 and 14 units
1:09:24equals how much?
1:09:2626, all right, perfect.
1:09:30Now let's talk about...or let's take
1:09:33this first, then move on to the next
1:09:36part.
1:09:39What is this?
1:09:40It is the...of the...of the...that
1:09:43exists for me, meaning what?
1:09:48Meaning, look here at each one, and you
1:09:50will find that you have something very
1:09:51simple, which is what?
1:09:55I am supposed to be able to zoom in from
1:09:56here, but it's not working.
1:10:03Ah.
1:10:06Okay, anyway, look, for example, at
1:10:08carbon, you will find carbon is what?
1:10:15Look at the phosphorus below it.
1:10:18Well, how are there numbers like that in
1:10:20this format, and it's in a format where
1:10:22there is a K and here...
1:10:26Here...
1:10:29How does it have these numbers when I
1:10:31supposedly just said above that the mass
1:10:33is 26, a whole number?
1:10:37It said to me, "You are forgetting
1:10:38something."
1:10:39I said, "What?" Didn't you tell me a
1:10:41little while ago that I have...
1:10:44And you told me, for example, I have
1:10:45carbon, there is carbon...
1:10:51And you told me that the ratio of this
1:10:53was in different percentages.
1:10:55I said to you, "Yes, I told you that."
1:11:00You said, "Yes."
1:11:01I tell you, this is something we cannot
1:11:03ignore.
1:11:05Now, I have a cube of carbon. Here is a
1:11:07cube of carbon; how would I know if the
1:11:09carbon in it is 12, 13, or 14? It could
1:11:12be anything.
1:11:13You might say its percentage is small,
1:11:15so you surely aren't that unlucky, but
1:11:17it isn't calculated like that; it is
1:11:19calculated that this cube could contain
1:11:21all three.
1:11:23It could be whatever the thing in front
1:11:25of me contains.
1:11:26So for me, I have the possibility of
1:11:28having the carbon in front of me be
1:11:30several types.
1:11:31And as long as it could be several types
1:11:33, I take that and say what?
1:11:35Well, I now need to know the mass of
1:11:38this cube; in what range will it be?
1:11:42So, how do we find out what that range
1:11:44is?
1:11:45Well, let's assume for a moment that
1:11:48it's going to be a calculation, right?
1:11:52I told you I have a bag, and in this bag
1:11:55, there are two empty balls and three
1:11:58shaded balls.
1:12:02So, if you were to ask me what the
1:12:04probability of the ball I have is, what
1:12:06would you do?
1:12:10You would take the, the, you would say,
1:12:12"Here is what you do," you multiply the
1:12:14percentage of that thing by the thing
1:12:17itself; for example, you take a ball
1:12:19like this and multiply it by its ratio.
1:12:23Good? Plus what? So its ratio is three
1:12:26out of a total of five.
1:12:28That there is the, what is it? The value
1:12:31of the percentage of the balls that are
1:12:33shaded.
1:12:35Which is their number divided by the
1:12:36total number, and you might get the
1:12:38other two as well.
1:12:39And the second one would be what? It
1:12:41would be two over five.
1:12:45Okay, this is stuff we've covered before
1:12:47, but I want you to give me something
1:12:48clearer to talk about.
1:12:52I will tell you, let's assume now, let's
1:12:54assume now that I have this carbon in
1:12:56front of me, and I want to know the mass
1:12:58of this carbon to be able to work with
1:13:01it and do my calculations.
1:13:04Good?
1:13:05So, what do I do?
1:13:07I say that I am multiplying the mass of
1:13:10each one, the number above it, by its
1:13:13percentage.
1:13:15Good, I multiply the mass by the
1:13:16percentage and add them all together.
1:13:19So I multiply the percentage by the mass
1:13:21, then I add, what do I do? I add them
1:13:24all up, so here you would say, "I will
1:13:27multiply this 12, all of it, all of it,
1:13:30all of it, by..." meaning I will divide
1:13:32it by 100, 12 times 98.9 divided by 100
1:13:35, that is considered the weight I will
1:13:38take if what?
1:13:39If what I have is 12, if what I have is
1:13:4112, here it is, and I have the 13 here.
1:13:46On what? On 100, and here is the 14,
1:13:49times what?
1:13:51Times its percentage, which is, whatever
1:13:53it is, divided by what?
1:13:55On what? On 100.
1:14:02And at that point, I will work with it
1:14:03in what? In grams, so now this is what?
1:14:06This.
1:14:09So I have summed up, I have taken the
1:14:11sum of more than one thing, and made
1:14:13something as if it were what? As if it
1:14:15were, but I cannot say what?
1:14:19I cannot say, "Take 12 and add it to 13
1:14:20and add it to 14 and divide them by
1:14:22three," why?
1:14:24Because their natural abundance is not
1:14:26the same, so I won't get that; what will
1:14:28I get? I will get what? Which is, for me
1:14:32, multiplying the what?
1:14:34By what?
1:14:35By its presence in the world, in nature
1:14:37, and here what?
1:14:38And add them together, nice, perfect,
1:14:41great, so here he says what?
1:14:45It has three, the first X is 40, this
1:14:49one is 41, this one 42, their presence
1:14:52is 72%, 9%, and 19%for each one, so it
1:14:55wants the atomic mass of X, which is
1:14:58found in the periodic table; let's not
1:15:01confuse it with its mass found in the
1:15:04mass number, which is what?
1:15:09How is it done? I mean here, for example
1:15:11, carbon, did it specify for me carbon
1:15:1312, 13, and 14? No, just carbon, so I
1:15:15want the atomic mass in X, so I will get
1:15:18the average of the three, then you tell
1:15:20me what?
1:15:21Okay, I'll take them one by one, I'll
1:15:24multiply the first one, which is 40, by
1:15:26the percentage over 100 and add it to
1:15:28whom?
1:15:30Multiplied by how much? By 9 over 100
1:15:33and add it to what? Here it is for me,
1:15:36here is
1:15:39I will multiply it by how much? By the
1:15:4142 over how much? Over 100, so this is
1:15:44for me what?
1:15:46Which is my atomic mass that I can add
1:15:49all together on the calculator, let's
1:15:51get a calculator and what? And what,
1:15:54let's see the
1:15:57The result, here is the bracket, here is
1:16:00this, here is this
1:16:05No, boss style
1:16:08And when I use the calculator on it
1:16:13Okay, we are here, alright, here we are
1:16:15, let's separate it completely so you
1:16:17can be comfortable, and here it is
1:16:21Here it is, here it is, here I have
1:16:27Here, what is it?
1:16:29This is here, here is
1:16:35Here is this, here is the first thing
1:16:42Add all of these together and see what
1:16:44it comes out to, I find it came out to
1:16:49So it came out to how much?
1:16:52Which one will it be? Here
1:16:57Which will be what? It will be
1:17:01So we now know how we solve the problems
1:17:03of what?
1:17:04How? Beautiful, okay, so it says here
1:17:07what? This is what?
1:17:09The monster, the fact that there is
1:17:10nothing higher than this
1:17:12I mean, it exists for me in nature as
1:17:15what? Two, one, so one wants the atomic
1:17:18mass, it says to me the atomic mass of
1:17:21copper is how much?
1:17:24So the atomic mass of copper
1:17:29In general, this is the, it wants the
1:17:31atomic mass, but it will be like what?
1:17:36Oh, it is not the opposite, I previously
1:17:38was given the percentage and the mass of
1:17:40each one and I would get the what?
1:17:42Here it gave me the atomic mass, so how
1:17:44will I deal with it?
1:17:45I will deal with it very simply, there
1:17:47is nothing simpler than this, what
1:17:48exactly will I do?
1:17:49I will tell it, well now, write for me
1:17:51the law you were working with.
1:17:54I was writing now the mass, so for
1:17:57example, the mass multiplied by its
1:17:59percentage and add it to
1:18:04And multiply it by its percentage.
1:18:07Equals in the end for me how much?
1:18:11This is what, this is the law I will
1:18:14work with, so here, mass multiplied by
1:18:16its percentage plus mass multiplied by
1:18:19its percentage, I will tell it this
1:18:22equals for me what?
1:18:26For example
1:18:29I come and tell it what?
1:18:30It says, okay, bring these here, this
1:18:32under this, just so it stays organized
1:18:39So I am what? Here is the law and here
1:18:41is what I what? That I substituted with
1:18:43, okay, I want to get these masses.
1:18:45I now have two ways, a way if I now know
1:18:48how to use the calculator, this way, and
1:18:50another way that I will solve it like
1:18:52this, now it was
1:18:57Now, if we assume the mass was half and
1:19:00half, it should land exactly in the
1:19:03middle, right?
1:19:05He said, "Correct."
1:19:07What if I found that it came...
1:19:10Here is A and here is B, and I found it
1:19:13landed in this spot, so what's happening
1:19:16?
1:19:18It's as if the larger share of A is like
1:19:20three-quarters of what I have, and the
1:19:23quarter of what I have is what?
1:19:27So, I've ended up closer to what?
1:19:30To A, so you could tell me, "Oh, so the
1:19:32most I can choose is," what should I
1:19:34tell you?
1:19:36Correct.
1:19:37Now, if you don't want to solve it with
1:19:38logic and want to solve it precisely,
1:19:39what do you do?
1:19:41I have a feature on the calculator
1:19:42called Shift Solve.
1:19:45I don't know if you've discovered it yet
1:19:48; Shift Solve on the calculator solves
1:19:50for any variable, which is X in my case
1:19:53here.
1:19:55Now, I have this unknown and that
1:19:57unknown here, but I'll tell you that you
1:20:00can turn these two into one unknown.
1:20:04Watch the magic: You'll tell me, if we
1:20:07say the ratio of A is X, great, then the
1:20:10ratio of B will be what?
1:20:13I'll say, "I don't know." No, you do
1:20:15know! He said what? He said I have
1:20:17either...
1:20:21The ratio of this and the ratio of that
1:20:23, if you add them—any ratio in the world
1:20:26, the sum of its parts is 100%.
1:20:28So if you say this one is X, then that
1:20:31one will be what?
1:20:33It will be 100 minus X. If I add these
1:20:36two together, won't it give me 100?
1:20:39He said, "Yes." So you can substitute
1:20:42for me by saying this one here is X...
1:20:47This one here is X, and you tell me that
1:20:50one is what?
1:20:57Here, A is...
1:21:01So here you say A is X, and that one is
1:21:04...well, this is X and that is B.
1:21:07Consequently, you now have one unknown
1:21:10instead of two. So you take the
1:21:12calculator and do what?
1:21:15You write this equation exactly as it is
1:21:18on the calculator.
1:21:20How do you write it as is?
1:21:23I'll tell you: you open your first
1:21:25parenthesis...
1:21:28Times X, see? There is A and there is X.
1:21:31That's the first parenthesis, plus the
1:21:34second parenthesis.
1:21:37What about this? Oh, there's something
1:21:40we forgot: we are dividing by 100. So we
1:21:43are dividing here by 100. I am
1:21:46multiplying by what?
1:21:48Times...here, first you tell me here:
1:21:51100 minus what?
1:21:54Minus X over what? Over B, and you close
1:21:57the parenthesis again. I've written this
1:22:00part. I get the equals sign from Alpha
1:22:02and Calc. I tell it Alpha and Calc
1:22:04equals how much?
1:22:08And then I tell it what?
1:22:10Wait, where is A?
1:22:14Oh, there’s a parenthesis we forgot.
1:22:16Parentheses here are very, very, very
1:22:18important. Here is the parenthesis. I’ll
1:22:20press it, and let’s see what it comes
1:22:22out to.
1:22:25So, what does x come out to for me now?
1:22:30Right here.
1:22:33What did x come out to for me?
1:22:37Which is what?
1:22:38He told me here, so I chose this one, it
1:22:40is what? It is the correct answer, but
1:22:43the exact precise answer is this, the
1:22:44percentage of the presence of what?
1:22:47Carbon, sorry, copper.
1:22:52If you didn't understand this part, the
1:22:53one new to you, go back and repeat this
1:22:55part once, twice, three, or four times,
1:22:57no problem.
1:22:59I don’t know if you’ve taken this in
1:23:01math or not, but anyway, here it is,
1:23:03everything is fine, good, and perfect.
1:23:05Let’s move up to this part, or just a
1:23:08quick second.
1:23:11Where?
1:23:17It is the part that I was going to
1:23:19explain to you, it and gamma, which is
1:23:24I mean, it’s not supposed to be included
1:23:26, but it came up in exam questions once
1:23:28, so I will solve its exam question for
1:23:29you so you know how it’s solved if
1:23:31something similar comes up, even though
1:23:32it’s not included as of now.
1:23:34Okay, first of all, here he says this is
1:23:36a question to quickly refresh our memory
1:23:38, he says what?
1:23:48So this is what? Every [unit] of [
1:23:51substance] in grams of...here it is,
1:23:54this is from...he wants to know the [
1:23:57property] of [substance].
1:24:06From [substance], cool? So now he tells
1:24:11me that I had every...
1:24:16What do I need now?
1:24:17I need in exchange for it, how much?
1:24:21In grams of what?
1:24:23Of what? The [substance], so this is the
1:24:25[substance] and this is what?
1:24:27So he now wants to know what will be for
1:24:30me the [amount] that I need from [
1:24:32substance], so here, above, it was in
1:24:35kilograms so I don’t get confused and
1:24:37choose immediately. This was [x] and
1:24:40this was kilograms.
1:24:41The kilogram now, for me, here it is; I
1:24:44want to choose volume in what? In [unit
1:24:47] or did I choose volume of what?
1:24:50I want to get [x] to get how much?
1:24:52To get [y].
1:24:55So I will get what? I will tell him,
1:24:57well, I have, he told me that every [
1:24:59unit] of [substance]?
1:25:01So if I want to get [x].
1:25:05I can.
1:25:08I mean, this I am still going to convert
1:25:10, so I come here and say this will be
1:25:12how many kilograms of [substance], great
1:25:14? I’ll say how many kilograms of what?
1:25:15Of [substance], so now to know this, I
1:25:17will multiply these together.
1:25:19But the [units] must be the same.
1:25:22How are the [units] the same? By
1:25:24converting them all to what? To [unit]
1:25:27so I can be able to know how it would be
1:25:31.
1:25:32Okay, so I’ll tell him, fine, you bring
1:25:35me now, so this is what? Which is 1000
1:25:38kilos. So you will go like this and tell
1:25:40me what? I mean, I will convert from [
1:25:42unit] to kilos by multiplying it by how
1:25:44much? Kilos.
1:25:46So I will remove the word ton and write
1:25:47kilo.
1:25:48Okay, I want to convert this kilo to
1:25:50grams, so I will multiply it.
1:25:53By 1000 again. Here it is, so that what
1:25:55? So that it becomes grams.
1:25:59So I have this as grams, this as grams,
1:26:01and the kilograms above, what are they
1:26:03for me?
1:26:04I mean, what are they for me? In this
1:26:08form. Okay, what is the answer he wants
1:26:10now? In liters, right?
1:26:13Well, he gave me
1:26:18As if it is the same
1:26:21So it is easier for me now after I get
1:26:24how many kilograms, to convert it to
1:26:26what?
1:26:27To volume using...so it is easier to
1:26:29keep it in the...that I'm working with
1:26:31and want to get in liters, so it is
1:26:33easier to make them all what? Kilograms
1:26:35.
1:26:35So I will go back before making this
1:26:37grams, and I will reach that it is what
1:26:39? Here is a kilo, and this...I will make
1:26:41it kilograms, so it becomes
1:26:45Meaning, as if I divided it by 1000 here
1:26:47, what is it? Kilograms.
1:26:49So I have made them all kilograms here,
1:26:51beautiful?
1:26:52What do I do then? I multiply them
1:26:54together and get the what? Which is what
1:26:57? A kilo of the...so how much is a kilo
1:26:59of the...how does that look? It will be
1:27:04Over
1:27:09Which is of the...that's it.
1:27:11I check this to see how much it comes
1:27:14out to be over...and I come here to say
1:27:17that I have
1:27:20Meaning here it's like what? Like seven
1:27:22zeros.
1:27:27The...the more...the subject becomes
1:27:33Uh, where?
1:27:36Here I will say
1:27:41Let's remove this
1:27:44Here what? The
1:27:50Here this, but when I do it, I put a
1:27:53bracket or I should have drawn a line
1:27:55here from the beginning
1:27:59Here, how much
1:28:11This equals how much
1:28:19Here is
1:28:29Let's work
1:28:35Like this, kilograms. I want to convert
1:28:37it to...what do I do? Or I say, what did
1:28:40it originally equal? It was equal to
1:28:42mass over...now he wants...right?
1:28:45So it will be what?
1:28:47I will swap the place of...and...so it
1:28:49will equal mass over...now I have the
1:28:51mass, right?
1:28:52The mass is how much?
1:28:57Over...which is how much?
1:29:00When I divide this by this, I check how
1:29:02much I get, I find it came out to be
1:29:10Which is which
1:29:12So, did I learn how the question is
1:29:13solved? Let's listen to it again if
1:29:15things aren't clear quickly
1:29:32Sweet, sweet, I am now...he tells me
1:29:35that I have each of them 25 grams, I
1:29:38added it to...of the...and I will look,
1:29:41I will find that he told me, he gave me
1:29:46I will look at the difference, I will
1:29:47find that what happened?
1:29:49That I was here at the? The water is
1:29:52supposed to be at the...at all of them.
1:29:54The water is supposed to be at what? At
1:29:56the...sweet?
1:29:58Beautiful.
1:29:59I found that the difference between them
1:30:00is how much each one increased.
1:30:02Right? How much each one increased like
1:30:04this. I will find that A, the volume of
1:30:08the rock will be this what?
1:30:10The largest volume.
1:30:12And B, this is...meaning that what it
1:30:13increased here is this. Meaning I can't
1:30:15look at it. But someone here wrote nine
1:30:16, someone here wrote three, and someone
1:30:18here might have written one. So the
1:30:19volume I increased here is greater than
1:30:21the volume I increased. The volume of A
1:30:22is greater than the volume of B, which
1:30:24is greater than the volume of what? Of
1:30:26C. So, do you know what the idea of the
1:30:28problem is? That right now he's telling
1:30:30me he wants to know which of them A, B,
1:30:32and C corresponds to what? From these X
1:30:34, Y, and Z. So, how do I identify them?
1:30:37I'll tell him now, you could ask me,
1:30:40which one of them has the largest volume
1:30:42, the bigger one or the smaller one?
1:30:45And I would say what? Well, look, what I
1:30:48know is that density equals mass over
1:30:50volume.
1:30:51So, if I want the largest [density],
1:30:53what would it have? It would have the
1:30:55smallest volume.
1:30:57So, largest [density] corresponds to
1:31:00smallest volume, because they are
1:31:03opposites.
1:31:05So, who among these is the smallest? C.
1:31:08And among X, Y, and Z, which is highest
1:31:12? Y. So Y is the one that forms [
1:31:14density] A, because it has the highest [
1:31:16density]. Now B is the one in the middle
1:31:19, who is in the middle? That's [density
1:31:21] B. So this [density] which is the
1:31:23highest—sorry, lowest—will have what?
1:31:26Highest [volume], which is like this, so
1:31:28it’s what? I'll say to him, where is [
1:31:30density] A located?[Density] A is in [
1:31:31material] A, so we'll cancel out...[
1:31:33Density] A is in [material] A, and [
1:31:35density] where is it?[Density] is in [
1:31:37material]...which is like this, which
1:31:39one? The one that is like this, because
1:31:41this is also like that. Well, for those
1:31:42who can't visualize the problem with me
1:31:44, listen to this part.
1:31:45Now, I have something that is what?
1:31:49I want to know now, why are they all the
1:31:51same [mass]? Why did I solve it this way
1:31:53? Because they all have the same mass.
1:31:54This mass is constant, so as [density]
1:31:56increases, volume decreases.
1:31:59So now, I’ll tell you, suppose you
1:32:01imagine with me that I have...
1:32:05Get me the volume for each one of these
1:32:07. I will tell you now, you said to me
1:32:08...
1:32:10You want the volume? Fine, divide mass
1:32:12by [density]. I will divide now by [
1:32:15density] and I will divide by [density]
1:32:17and I will divide by [density].
1:32:19When I get the result for each one of
1:32:21them, which one will be the highest
1:32:23value?
1:32:24It will be...
1:32:26And who else is the highest value?
1:32:28Over what? Over...and who else is the
1:32:30highest value, which is the last one?
1:32:31Which will be...
1:32:34So, did you understand how things are
1:32:35working now?
1:32:36This is the highest, this is the middle
1:32:38one, and this is the lowest, okay?
1:32:42Well, he says they are present in this
1:32:44number. Count with me, come on. After
1:32:46...here is one, here is two, here is
1:32:48three, here is four. Is this zero
1:32:49included with us or not? I tell you, as
1:32:51long as the zero is after [the decimal]
1:32:53, then what? Then it's included. So that
1:32:54makes how many? Five.
1:32:56Well, this question...
1:33:03We had two things for us that are what?
1:33:06We are talking about them.
1:33:12I don't remember if I told you this in [
1:33:14the lesson], but if I did, you've
1:33:15understood it and are reviewing it, and
1:33:16if I didn't, then I'll let you...Let you
1:33:18know it.
1:33:19The difference between [extensive and
1:33:22intensive properties] for me now is
1:33:24whether it depends on the quantity or
1:33:26not.
1:33:27What does that mean? Depends on [the
1:33:29amount] or not?
1:33:31What does "depends on" mean? I mean, for
1:33:33example, have you ever seen that the [
1:33:36density] of...if I am in the sea—let's
1:33:38leave the sea aside because it's salt
1:33:41water.
1:33:42If I now got water from the tap, okay? I
1:33:45filled a cup with this tap water, and I
1:33:48filled a large bucket with it.
1:33:51The water here and the water there, what
1:33:53are they like? You’d say, for example,
1:33:56they’re both the same, right?
1:33:59They’re both the same.
1:34:01He said, what if I go to boil both, boil
1:34:03the water in the cup or boil the water
1:34:04in the what? In the what? The large
1:34:07bucket. He said I found that for both,
1:34:09what will happen?
1:34:11Their temperature will be at what?
1:34:14It will be at 100. Did 100 change?
1:34:18No. Even though what? This is a cup and
1:34:21this is a bucket, so that means that [
1:34:23intensive/extensive] properties, what
1:34:26are they like?
1:34:27They don't depend on the amount. As long
1:34:30as the thing doesn't depend on the [
1:34:32size], then [intensive], which is what?
1:34:35Which is, which is what? The [intensive
1:34:37property].
1:34:41It doesn't depend on the amount.
1:34:43Doesn't depend on what? On the amount,
1:34:45but the [extensive property], what is it
1:34:47like? It depends on the amount. Okay.
1:34:49Now, here, what are we at?
1:34:54We said the [intensive] and explained it
1:34:56, so it's not our focus, and the [
1:34:57extensive] is not our focus. The [
1:34:58chemical reactivity], what is it like?
1:35:01This [reactivity] also doesn't depend on
1:35:03the amount. I have this, it will react
1:35:05with the [reagent] just as this will
1:35:07react with the [reagent], so it will
1:35:09react regardless. For me, what is it?
1:35:11It’s irrelevant. But now look at the
1:35:12mass. If I go to measure the weight of
1:35:14the cup and the weight of the bucket,
1:35:15I'll find this is, for example, what?
1:35:17I’ll find this is 100 grams, I’ll find
1:35:18this is, for example, what? I’ll find
1:35:20this is 10 kilos.
1:35:21So, consequently, this is what?
1:35:23Consequently, it varied based on what?
1:35:25Based on what? On the [amount] that I
1:35:28have. So for me, this mass is what? What
1:35:30else besides mass? Something like what?
1:35:34Like [volume], something like the what?
1:35:38All these vary. So now, I got what? I
1:35:41got a wooden board. I cut this wooden
1:35:43board into two pieces. One piece now
1:35:46became small, 10 cm. And the other piece
1:35:48, it was a meter, the other piece became
1:35:4990 cm. So now, the length is different,
1:35:51even though both are the same thing.
1:35:53Both are the same wood. So, do you
1:35:55understand the factor of the [extent]
1:35:56how it works? Great.
1:35:57He tells me here, here is X forty, below
1:36:01is Y, and above is Z below.
1:36:04He says now, find me these atoms, which
1:36:07of these is correct?
1:36:10Right?
1:36:11So I’ll tell you something, let's start
1:36:14by gathering the first thing that comes
1:36:16to mind: 20 and 20. As long as they are
1:36:1820 and 20, then these two are the same,
1:36:21so they are both the same [element].
1:36:23Consequently, what will it be? It will
1:36:26be that X and Y are...
1:36:30I am like this...
1:36:32Beautiful? Beautiful. Okay.
1:36:34What else can I observe?
1:36:37Look, look at X and Z. X and Z, what are
1:36:39they like?
1:36:41X and Z, both, when I subtract the
1:36:43number of [protons] from the top minus
1:36:45the atomic number: 40 minus 20 gives me
1:36:4820, and 39 minus 19 gives me also how
1:36:50much? 20. So this equals the same number
1:36:53of neutrons, so they are here what?
1:36:58And look at Y and Z, you’ll find that
1:37:00both have how many?
1:37:03This is their mass number, so what will
1:37:06Y and Z be?
1:37:08They will be
1:37:11Okay? So, do you understand how things
1:37:12are now? This and this are what? These
1:37:15two together
1:37:18Y and Z together, so let's see which of
1:37:20these is present? X and Y, did we say X
1:37:23and Y? No, we didn't, so they are out.
1:37:27Let's check.
1:37:29X and Y, when I subtract like this, and
1:37:31here the two are different, so this is
1:37:32wrong.
1:37:34X and Z, what will I say? I will say X
1:37:37and Z are correct. Why? Because the two
1:37:40have what?
1:37:42Now, Y and Z, let me look. Did I say Y
1:37:44and Z? No, Y and Z, this is 20 and this
1:37:47is 19 for their atomic number, so it is
1:37:49wrong.
1:37:50X and Z, no, we said who? Y and Z, so
1:37:52for me this is what? Wrong. Beautiful?
1:37:55Beautiful.
1:37:56Now, this is the question I was telling
1:37:58you about a moment ago, which is what
1:38:00came here. It tells me what? Which of
1:38:02these reactions produces alpha, beta,
1:38:03and gamma?
1:38:05So we will figure out, we won't know
1:38:06anything except what their composition
1:38:08consists of?
1:38:09Okay, so here with me real quick, alpha
1:38:12is a helium, what is it? It has no
1:38:15electrons, so it is helium like this. So
1:38:18what happens? Meaning a mass number of
1:38:20four and two what? And two protons at
1:38:23the bottom.
1:38:24Beta is an electron, beta is what? It is
1:38:28an electron, gamma is just energy and
1:38:30that's it.
1:38:31So let's look at the question. Which we
1:38:32have now enlarged the question. And we
1:38:34came to look here at this question. And
1:38:35we looked here.
1:38:37Here this is uranium.
1:38:39And it turned into Th. Right here.
1:38:42And it produced X with it.
1:38:44And here this hydrogen was 3, 1. It
1:38:46became 3, 2 helium. And it produced Y
1:38:48with it.
1:38:49And here this Te was.
1:38:52It also became Z. So now I will do
1:38:55something quick and tell you what?
1:38:59What is this?
1:39:00Take this Te here, it entered and exited
1:39:03the same way.
1:39:05Therefore, as long as nothing has
1:39:07changed, then it only emitted energy,
1:39:09which is who?
1:39:10Which is gamma rays, so it produced what
1:39:13?
1:39:13Gamma rays and that's it, so we know
1:39:15that what? That gamma rays, its symbol
1:39:17which is this, this is what? It is in Z.
1:39:20So you come to look at who has this? A
1:39:22and B have it.
1:39:24Beautiful. So now X and Y, one of them
1:39:27is alpha and one of them is what? One of
1:39:29them is beta.
1:39:31You might say to me, how do I
1:39:32distinguish between them? I told you now
1:39:34, you distinguish between them by what
1:39:35happens?
1:39:37Now I am taking beta.
1:39:41Good, beta is what?
1:39:45It consists of me releasing an electron
1:39:49.
1:39:51So how does this electron come out?
1:39:54He told me, aren't the neutrons here for
1:39:56you, what are they?
1:39:58The neutrons were, they are...he told me
1:40:02yes.
1:40:03Meaning it has, as long as
1:40:06I told you yes. He said, okay, you will
1:40:09take
1:40:11And split it.
1:40:13It will give you, and it will give you a
1:40:16proton.
1:40:17Right?
1:40:19Yes, meaning, and a proton will produce
1:40:20what for me then?
1:40:22I mean, I divided them, great.
1:40:24Well, I divided them, which is the
1:40:28information I have, so therefore, when I
1:40:31had three and one.
1:40:34Okay, and it transformed, so here it's
1:40:37three and two.
1:40:38What happened?
1:40:40I took from here, so it became as if...
1:40:45Great, now this is, or I took this
1:40:49neutron here, let's erase this, oh my,
1:40:53here is the hydrogen that was formed for
1:40:58me.
1:41:00I took this neutron and converted it, it
1:41:04broke down into a proton, and this
1:41:07proton will do what?
1:41:10It will be added to what? To this
1:41:13hydrogen again.
1:41:14When I return this proton, what will
1:41:16happen? The one below will change, it
1:41:18will become what? It will be two at the
1:41:20bottom. Consequently, the one at the top
1:41:22will be what? It will also increase by
1:41:24one, it will be three.
1:41:25So when I find that what happened to me
1:41:27happened in...
1:41:29Or...
1:41:32Never mind your mass number that you
1:41:35have, so that...So it is clear to you,
1:41:37here the mass, I found it constant.
1:41:41As long as it is constant, and I found
1:41:44that the proton...
1:41:46So what is this?
1:41:49I found the mass is constant, and the
1:41:51proton, so what is this?
1:41:54So we can say that Y is what? What is Y
1:41:57?
1:41:58So which one is Y, beta, which means X
1:42:02is X, beta is Y, and...And gamma is what
1:42:05? It is Z. So gamma is what?
1:42:09It is Z, beta is Y, and alpha is X. But
1:42:11why is alpha X?
1:42:14I'll tell you, look, as long as you have
1:42:16the...the number at the top, the N, it
1:42:17increased from two, as long as it
1:42:19increased for you, this means that it is
1:42:21what?
1:42:22That it took an alpha...Alpha.
1:42:28But this part, this piece is also not
1:42:30very accurate in the question, I mean I
1:42:33don't want you to know anything other
1:42:36than that these two are correct, but
1:42:38this one isn't very accurate, so you
1:42:41figured out the answer from the last two
1:42:44, cool.
1:42:45And also, this question, I can't answer
1:42:47it for you and have you fully understand
1:42:49it until you take it and understand this
1:42:51concept of alpha, beta, and gamma, but
1:42:52this is something to get you by for now
1:42:54.
1:42:55Okay.
1:42:58Which things will go towards the cathode
1:43:00?
1:43:01So you say to me, what is this cathode?
1:43:05I, this cathode, I haven't taken
1:43:08anything but the cathode, I come and
1:43:10tell you, no, the cathode usually is
1:43:13something, so now what?
1:43:16I mean, the cathode now for me is
1:43:19something, so which of these in front of
1:43:22me will move towards the cathode?
1:43:26I want something to go towards the...so
1:43:29surely to go towards the...now this
1:43:31means what?
1:43:34This means that since it will go towards
1:43:36the..., this means it is which of these
1:43:39, or...
1:43:41This thing, I mean which of these is the
1:43:42one that will be attracted towards it?
1:43:46You will find that the cathode for you
1:43:48is negative, so as long as, sorry, the
1:43:50cathode for you is, since it is, then
1:43:53what is it now?
1:43:55I want something negative that would be
1:43:56attracted to it; what about this Alpha?
1:43:58What is this Alpha for me and what is
1:44:01this Beta for me? What is this Gamma,
1:44:03what is it? Actually, it’s just that the
1:44:06word "cathode" here is a mistake.
1:44:10So, in this case, whoever set this
1:44:11question is wrong, because they have to
1:44:13tell me what kind of cathode it is.
1:44:16Because if it were the cathode from the
1:44:18cathode ray tube we were working with,
1:44:19it would be negative, so I would choose
1:44:21Alpha without thinking, but if he means
1:44:23the cathode of batteries, then what is a
1:44:24battery cathode?
1:44:26It is positive, so I would choose Beta.
1:44:29So you should know both, God willing, in
1:44:30case this question comes up and you
1:44:31don’t get a cathode ray tube again, so
1:44:33you don't get confused, what will you do
1:44:34?
1:44:36We choose what we said it is? We will
1:44:38choose Beta because we want what?
1:44:39Something negative to go to the positive
1:44:41. Okay, this question tells me.
1:44:50So this question is similar to the one
1:44:52we solved a little while ago, just a bit
1:44:54bigger.
1:44:55Here we have.
1:44:58Okay, here we have Na, Na, and F
1:44:59negative.
1:45:01Na positive, when you subtract one it
1:45:02becomes 10, and this Na is already 10,
1:45:04and F, when it takes one, also becomes
1:45:0610, so this is what?
1:45:07It is the correct answer.
1:45:18So here, what?
1:45:20He’s telling you which of these salts
1:45:21has the number of electrons of the
1:45:22positive ion equal to the number of
1:45:23electrons of the negative ion, so what
1:45:24will you do?
1:45:26You will take each one of them and break
1:45:27it down into positive and negative.
1:45:32When we take each of these compounds and
1:45:34start to see what the positive ion and
1:45:36the negative ion are in them, we will
1:45:37take them.
1:45:39As we used to do before in middle school
1:45:42, let’s look.
1:45:44Here is MgCl2, good, and on the other
1:45:46side for me is CaO, and here is LiCl,
1:45:49and here is K2S.
1:45:51Let’s take each one of them. MgCl2, do
1:45:54you remember what we used to do when we
1:45:57took this compound in middle school? We
1:46:01used to start saying what?
1:46:04Oh, we find the valency of each one.
1:46:06Since I went with the Mg by 2 and came
1:46:09with the Cl here by 1, this means that
1:46:12the valency of the Mg is what?
1:46:14It’s 2.
1:46:16It’s what? B1.
1:46:18Well, for calcium, I know that oxygen or
1:46:21calcium, whatever it is, I know one of
1:46:24them is 2. So, since I went there with 1
1:46:27and came here with 1, I know that this
1:46:29one's valency is 2 and this one's is 2.
1:46:32Now, lithium and [element], I know that
1:46:35lithium is 1 for me, and I know what...
1:46:38I know that [element] is 1 for me.
1:46:41Therefore, I'll tell him: this is 1 and
1:46:44this is 1. Now, [element] is normal.
1:46:47[Element] now came with 2 and [element]
1:46:50went with 1, so this one's valency is 1
1:46:53and this one's valency is 2. Great.
1:46:56So, I take the [element] and it means it
1:46:59will do [action] here; the [element]
1:47:01expresses to me that it will do [action
1:47:04].
1:47:07To how much exactly of the [element]
1:47:09that I have? Great. He said it's great.
1:47:11Well, the [element] is 2, so the [
1:47:13element] will show me what it has in the
1:47:15[element].
1:47:18How many were there, and in the [
1:47:19element], how many will they be?
1:47:20In the [element], how much was the [
1:47:22element]? When it does [action] for 2,
1:47:25it will be 10. How much was the [
1:47:27element]?
1:47:29When it does [action], it will be...Are
1:47:31these two the same?
1:47:33No, so for me, the first one is wrong.
1:47:36Calcium was how much? It says 20 here.
1:47:39When it does [action] for 2, it will be
1:47:4118. Oxygen was how much? It was 8. When
1:47:44it does [action] for 2, it will be 10.
1:47:46Are these equal? No. Lithium and [
1:47:48element], how much was lithium? It was
1:47:503. When it does [action], it will be 2.
1:47:52How much was the [element]? When it does
1:47:54[action] alone, it will be...Are these
1:47:56equal?
1:47:57No. The [element] when the [element]
1:48:00that it does alone, how much will it be
1:48:02? It will be...So this [element], when
1:48:04it is originally how much?
1:48:07It will do [action] for 2, it will be
1:48:08what? It will be like this. So, I tell
1:48:11him: these two are, yes. And I say to
1:48:13you: correct. We are now saying [
1:48:14element], so you know that [element]—
1:48:16who? Why do I call this [element]? Why
1:48:18do I call this [element]? Because the
1:48:20one on the left is the what?
1:48:22The metal, and the one on the right is
1:48:23the what?
1:48:24The non-metal.
1:48:27Alright, so we are what? We have
1:48:29reviewed the [element].
1:48:32We explained them and solved a nice
1:48:34number of questions, through which you
1:48:36can, God willing, go into the exam and
1:48:37sort things out. If you want to solve
1:48:39more things, if there is something
1:48:41specific you have that you want me to
1:48:43solve for you, send it to the group, or
1:48:45if there is anything, I will send it to
1:48:47you right away.
1:48:48I'm with you all day today, so anything
1:48:50you need, send it immediately.
1:48:51See you, bye.
1:48:53God be with you, guys.

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