AQA GCSE Physics in 10 Minutes! | Topic 3 - Particle Model of Matter — Transcript

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1. 0:00in this video we will be looking at GCSE
2. 0:02physics topic three and that is particle
3. 0:04model of matter here are the subtopics
4. 0:07we're going to be looking at throughout
5. 0:09this video as always these pages will be
6. 0:12available on my Etsy which is linked in
7. 0:14the description thank you very much for
8. 0:16watching and I hope you enjoy first of
9. 0:19all we have particle model this involves
10. 0:22solids liquids and gases and we're just
11. 0:25going to talk about the properties of
12. 0:26each of these three so solids have a
13. 0:29strong for force of attraction between
14. 0:31the particles as you can see they're in
15. 0:32a very fixed regular structure and when
16. 0:35they transfer energy they vibrate so if
17. 0:38you heat one end of a solid the
18. 0:41particles will vibrate and it will pass
19. 0:42it on kind of like a Mexican wave type
20. 0:44thing and you'd also say they have a
21. 0:46high particle density so there's a lot
22. 0:49of particles within a certain
23. 0:51space moving on to a liquid they have
24. 0:54weaker forces of attraction particles
25. 0:56move past each other in an irregular
26. 0:59structure so you can see if you compare
27. 1:00the solid to the liquid there is much
28. 1:02more of an irregular structure going
29. 1:05on and typically the particles will have
30. 1:07more energy than the solids and they are
31. 1:10also less dense than the solids because
32. 1:12as you can see there is a lot more air
33. 1:14gaps between the particles compared to
34. 1:16the
35. 1:17solids and finally we have the gas there
36. 1:19is almost no force of attraction between
37. 1:21them they move randomly in any direction
38. 1:26they always will fill the
39. 1:28container the particles typically will
40. 1:30have more energy than other states
41. 1:32because they are always flying around
42. 1:34and you would say they have a very low
43. 1:37density next we have density so density
44. 1:41has an equation behind it and it is mass
45. 1:43over
46. 1:44volume again if you haven't used the
47. 1:46triangle before please learn how to use
48. 1:49it if you don't know how to use it let
49. 1:50me know down below and I'll explain it
50. 1:52to you if you ever forget what the
51. 1:54equation for density is try and remember
52. 1:57some of the units for it and it makes it
53. 1:59much easier so as you can see the
54. 2:01density units are kog per M cubed and if
55. 2:05you look at the units for both mass and
56. 2:08volume you have kilogram and meters
57. 2:10cubed and because you're dividing them
58. 2:13that is why the density units are
59. 2:15kilograms per M cubed if you were
60. 2:18multiplying them it would just be
61. 2:20kilogram M cubed all as one thing but
62. 2:23that division in there that slash helps
63. 2:25you realize that you divide the two
64. 2:27things rather than times them
65. 2:30finding the density of a regular
66. 2:33objects so the problem first of all here
67. 2:36is if we had just like a cube a cuboid a
68. 2:39cylinder that kind of thing it makes it
69. 2:41very easy because obviously we can use a
70. 2:43balance or scales to find the mass of it
71. 2:47and then the volume just comes with any
72. 2:49equations that we've learned in the past
73. 2:50with maths or physics so for example a
74. 2:53cube You' just do the width times the
75. 2:55height times the depth however with an
76. 2:58irregular object you would want to do
77. 3:00the method that I'm about to tell you so
78. 3:03you fill a Eureka can with water and you
79. 3:07place the object into the water a
80. 3:08eurekka can is just a form of container
81. 3:12where you fill the water up to the
82. 3:13maximum height and then if you put
83. 3:16something in that displaces the water
84. 3:18and pushes it up any water that is
85. 3:21displaced will come out of a kind of
86. 3:23Hose type thing and can be caught in
87. 3:25another
88. 3:27container and then the amount of water
89. 3:29that is dis placed or removed from the
90. 3:30can is going to be the volume that you
91. 3:33have put in as long as it's fully
92. 3:34submerged so always make sure that is
93. 3:36the case as well and then because of
94. 3:39that you then have the volume and the
95. 3:40mass and you can work out the density of
96. 3:41it using the equation in front of
97. 3:44you next we have internal
98. 3:47energy so internal energy is the total
99. 3:50energy that A System's particles have in
100. 3:52their kinetic and potential energy
101. 3:55stores heating a system will increase
102. 3:57the energy in the particle's kinetic
103. 3:59energy doors making them move faster and
104. 4:02ultimately increase the internal energy
105. 4:05if the internal energy increases enough
106. 4:07this will result in a change in state so
107. 4:10just to clarify a system is just an area
108. 4:14where different reactions are taking
109. 4:16place so a system could be for example
110. 4:19in the diagram that I've drawn just
111. 4:20inside that container of water so in the
112. 4:24bottom half of this slide on the left
113. 4:26hand side I've got just a regular
114. 4:28container of water that might have just
115. 4:30been poured out of the tap and then on
116. 4:32the right hand side if we heat that up
117. 4:35all of a sudden the internal energy is
118. 4:37going to go from 10 to 100 and the
119. 4:40reason for this is because as we talked
120. 4:42about right at the start those particles
121. 4:44inside the water are getting heated up
122. 4:46so they get a lot of energy so they're
123. 4:48moving around and bouncing off the
124. 4:49containers getting a load of kinetic
125. 4:51energy some of those things will be
126. 4:53heating up to a point where they can
127. 4:55evaporate and turn into a gas so that is
128. 4:57your change in state but overall that is
129. 4:59why the internal energy is increasing in
130. 5:02this
131. 5:04system next we have specific latent heat
132. 5:08so this is simply The energy needed to
133. 5:10change the state of a
134. 5:13substance if you go by the proper
135. 5:16definition that you might want to say in
136. 5:17a test it will be something along the
137. 5:19lines of the energy needed to change the
138. 5:21state of one kilogram of a substance to
139. 5:23be very
140. 5:24specific so the diagram on the left hand
141. 5:27side is temperature up the y axis and
142. 5:30time across the x-axis when a substance
143. 5:33gets heated energy goes into increasing
144. 5:36the particles energies so that would be
145. 5:38again the kinetic energy the internal
146. 5:39energy that kind of stuff this results
147. 5:42in a temperature
148. 5:44increase during a change of state this
149. 5:47energy goes into breaking bonds so the
150. 5:49temperature increas is stopped while
151. 5:51this happens because breaking bonds is a
152. 5:54very energy intensive
153. 5:56process again we have an equation here
154. 5:58energy is Mass times specific latent
155. 6:01heat and again you can use those units
156. 6:03if you ever forget that because specific
157. 6:06latent heat Jewels per kilogram if we
158. 6:09were to rearrange this equation to get
159. 6:11the specific latent heat to be the
160. 6:13subject we'd be dividing by the mass
161. 6:15leaving us with Jews divided by the
162. 6:18kilogram energy divided by mass and
163. 6:20again you can use the triangle to do
164. 6:22this if you
165. 6:24prefer and our final slide is particle
166. 6:27motion in gases specifically the
167. 6:29pressure in gases gas pressure is
168. 6:32technically the force exerted per unit
169. 6:35area the gases will move randomly inside
170. 6:37a container and collide with both walls
171. 6:39of the container and other
172. 6:41particles in a sealed container the
173. 6:45pressure is the total force exerted on
174. 6:47the walls of the
175. 6:49container so if you've got 100 particles
176. 6:52in a big room the pressure is not going
177. 6:56to be that high because there's a
178. 6:58massive space for those 100 particles to
179. 7:00fill whereas if you shrink that room
180. 7:03down into a little 1 cm cubed box the
181. 7:07pressure is going to be massive because
182. 7:08all of those 100 particles have to fit
183. 7:10in there and they're going to be
184. 7:12bouncing off the walls left right and
185. 7:13center and it's going to cause the
186. 7:14pressure to go up massively because the
187. 7:16force on the walls is massive as
188. 7:20well and that sums up the end of
189. 7:22particle model of matter thank you very
190. 7:25much for watching please like And
191. 7:26subscribe if you found it useful and I
192. 7:28will see you in the next one