3. Particle Model of Matter

Question 1

1. Describe the arrangement of the particles in a liquid

Answer 1

1. particles touching but randomly organised

Question 2

2. Compare the properties of a liquid and gas

Answer 2

2. Liquid can pour but can’t compress, more dense than gases. Gas can pour and can compress as there is lots of space between particles.

Question 3

3. What is melting?

Answer 3

3. Solid to liquid. Bonds break and particles can move over each other.

Question 4

4. What is condensing?

Answer 4

4. Gas to liquid. Bonds form.

Question 5

5. How can we tell from a graph that a change of state is occurring?

Answer 5

5. The temperature doesn’t change.

Question 6

6. For a given amount of a substance when do its particles have the most energy?

Answer 6

6. As a gas.

Question 7

7. Which energy stores make up internal energy?

Answer 7

7. Kinetic energy store (how much they are moving) and Potential energy store (how far apart the particles are)

Question 8

8. Why does the temperature rise when a substance is heated?

Answer 8

8. Energy goes in to the kinetic energy store.

Question 9

9. Which energy store is filled when the energy causes a substance to evaporate?

Answer 9

9. The potential energy store

Question 10

10. Define density.

Answer 10

10. Mass per unit volume

Question 11

11. What are the units for volume?

Answer 11

11. cm3 or dm3

Question 12

12. If something is more dense what does that mean?

Answer 12

12. That the same volume of it would have a higher mass

Question 13

13. How do you calculate the volume of a regular object?

Answer 13

13. Length x width x height

Question 14

14. How do you calculate the volume of an irregular object?

Answer 14

14. Put it into water and measure the amount of water displaced

Question 15

15. What is latent heat?

Answer 15

15. The energy transferred to a substance when it changes state

Question 16

16. When a substance changes state why does the temperature not increase?

Answer 16

16. The energy goes into the potential energy store (and not the kinetic store which changes the temperature)

Question 17

17. What is specific latent heat?

Answer 17

17. The amount of energy needed to change the state of 1kg of a substance

Question 18

18. What is specific latent heat of vaporisation?

Answer 18

18. The amount of energy needed to evaporate 1kg of a substance

Question 19

19. Describe the motion of gas particles

Answer 19

19. Move randomly at high speeds in all directions

Question 20

20. What causes gas pressure?

Answer 20

20. Gas particles colliding with the surface of a container

Question 21

21. How does temperature affect gas pressure?

Answer 21

21. Higher temperatures = higher gas pressures (the gas particles move faster and so collide with the surfaces more often and with more force)