Topic 14 & 15 Particle model, forces and matter

Question 1

1 Name the three states of matter.

Answer 1

solid, liquid, gas

Question 2

2 Which of the three states of matter can be compressed?

Answer 2

gases

Question 3

3 Why can gases be compressed?

Answer 3

particles are far apart

Question 4

4 Which of the three states have a fixed volume?

Answer 4

solids and liquids

Question 5

5 Why do substances in these states have a fixed volume?

Answer 5

particles are held together by bonds

Question 6

6 Why do solids keep their shape?

Answer 6

Bonds between particles are very strong

Question 7

7 Name a physical change.

Answer 7

any change of state named, such as melting, freezing

Question 8

8 What does the density of a substance tell you?

Answer 8

the mass for a certain volume

Question 9

9 What two quantities do you need to know to calculate density?

Answer 9

mass and volume

Question 10

10 What are the units for these two quantities?

Answer 10

kg and m3; accept g and cm3

Question 11

11 What are the units for density?

Answer 11

kg/m3 or g/cm3

Question 12

12 What is the equation for calculating density?

Answer 12

density = mass/volume

Question 13

13 What usually happens to the density of a substance when it melts?

Answer 13

decreases

Question 14

14 Why does this happen?

Answer 14

particles are closer together in a solid than in a liquid

Question 15

15 What happens to the mass of a substance when it melts?

Answer 15

stays the same

Question 16

16 Is evaporating a physical or a chemical change?

Answer 16

physical

Question 17

17 Why is evaporation a physical change?

Answer 17

no new substance is made

Question 18

18 How is thermal energy stored in a substance?

Answer 18

movement of the particles

Question 19

19 What does temperature tell you about the particles in a substance?

Answer 19

how fast they are moving/vibrating

Question 20

20 What factors affect the amount of thermal energy stored in a substance?

Answer 20

mass, temperature, material

Question 21

21 What property of a substance tells you about the movement of its particles?

Answer 21

temperature

Question 22

22 How can you reduce the amount of thermal energy transferred between an object and its surroundings?

Answer 22

use insulation

Question 23

23 Name two insulating materials.

Answer 23

wool, foam, bubble wrap, or any other sensible suggestions

Question 24

24 Why does a kettle full of water store more energy than a cupful of water at the same temperature?

Answer 24

greater mass of water

Question 25

25 Give two other quantities that affect the amount of thermal energy stored in an object.

Answer 25

temperature and material

Question 26

26 What does specific heat capacity mean?

Answer 26

energy needed to raise 1kg of a substance by 1C

Question 27

27 What happens to the temperature of a substance being heated when it changes state?

Answer 27

temperature stops rising while the change in state is happening

Question 28

28 Why does this happen?

Answer 28

energy is being used to break bonds between particles

Question 29

29 What does specific latent heat mean?

Answer 29

energy needed to change the state of 1kg of a substance

Question 30

30 What are the units for specific latent heat?

Answer 30

J/kg

Question 31

32 Give the three factors that affect the amount of thermal energy stored in a substance.

Answer 31

mass, temperature, material

Question 32

33 What is the unit for specific heat capacity?

Answer 32

J/kg/øC

Question 33

34 What symbol is used for change in thermal energy?

Answer 33

Q

Question 34

36 What symbol is used for specific heat capacity?

Answer 34

c

Question 35

37 What does specific latent heat meant?

Answer 35

energy needed to change the state of 1ÿkg of a substance

Question 36

38 What are the units for specific latent heat?

Answer 36

J/kg

Question 37

39 Describe the arrangement of particles in a gas.

Answer 37

far apart and moving around quickly

Question 38

40 What causes gas pressure?

Answer 38

forces from particles hitting the walls of the container

Question 39

41 How are temperature and kinetic energy related?

Answer 39

Temperature is a measure of the average kinetic energy of the particles.

Question 40

42 What causes pressure in a gas?

Answer 40

forces from particles hitting the walls of the container

Question 41

43 What is the unit for pressure?

Answer 41

pascal, or N/m2

Question 42

44 Why does the pressure of a gas increase when it is heated?

Answer 42

particles move faster, hit the walls harder and more often

Question 43

45 What name do we give the temperature at which particles would have zero energy/pressure?

Answer 43

absolute zero

Question 44

46 What is 0K in degrees Celsius?

Answer 44

-273øC

Question 45

47 How do we describe something that deforms but returns to its original shape when forces are removed?

Answer 45

elastic

Question 46

48 What do we call the difference between a spring?s stretched length and its original length?

Answer 46

extension

Question 47

49 How does the force needed to stretch a spring change as the spring gets longer?

Answer 47

increases

Question 48

50 A graph of a relationship between two variables is a straight line through the origin. How do we describe a relationship such as this?

Answer 48

directly proportional

Question 49

51 What word do we use to describe something that deforms but returns to its original shape when forces are removed?

Answer 49

elastic

Question 50

52 What word do we use to describe something that deforms and does not return to its original shape when forces are removed?

Answer 50

inelastic

Question 51

53 What does a linear relationship on a scatter graph look like?

Answer 51

a straight line

Question 52

54 What is the difference between the graphs for a linear and a directly proportional relationship?

Answer 52

The graph for a directly proportional relationship passes through the origin; a graph for a linear one does not necessarily do so.

Question 53

55 Describe the relationship between the force on a spring and its length, for small forces.

Answer 53

linear

Question 54

56 Describe the relationship between the force on a spring and its extension, for small forces.

Answer 54

directly proportional

Question 55

57 What happens to the relationship between the force on a spring and its length or extension when the forces become very large?

Answer 55

becomes non-linear

Question 56

58 Describe the relationship between the force on a rubber band and its length.

Answer 56

non-linear

Question 57

59 What is the spring constant of a spring?

Answer 57

force needed to produce a 1m extension

Question 58

60 What is the equation linking the spring constant with the force and extension?

Answer 58

force = spring constant x extension