The particle model of matter

Question 1

What is the Law of Displacement?

Answer 1

An object that is completely submerged in water will replace an amount of fluid equal to its own volume.

Question 2

What is the arrangement of solids?

Answer 2

Particles held next to each other in fixed positions by strong forces of attraction.

Question 3

What is the movement of solids?

Answer 3

Vibrate about fixed positions.

Question 4

What are the properties of solids?

Answer 4

• High density.
• Fixed volume.
• Fixed shape.

Question 5

What is the arrangement of liquids?

Answer 5

• Particles in contact.

- Forces of attraction between particles are weaker than in solids.

Question 6

What is the movement of liquids?

Answer 6

Free to move randomly around each other.

Question 7

What is are the properties of liquids?

Answer 7

• Lower density than solids.
• Fixed volume.
• Can flow - shape not fixed.

Question 8

What is the arrangement of gases?

Answer 8

• Particles spread out.
• Almost no forces of attraction between particles.
• Large distance between particles.

Question 9

What is the movement of gases?

Answer 9

Move randomly at high speed.

Question 10

What are the properties of gases?

Answer 10

• Low density.
• No fixed volume or shape.
• Can be compressed and can flow.
• Spread out to fill all available space.

Question 11

What is internal energy?

Answer 11

The sum of the total kinetic energy and the total potential energy.

Question 12

What increases a substance’s internal energy?

Answer 12

Heating the substance.

Question 13

What is latent heat?

Answer 13

The energy transferred when a substance changes state.

Question 14

What is specific latent heat?

Answer 14

The energy required to change 1kg of a substance with no change in temperature.

Question 15

What is the specific latent heat of fusion?

Answer 15

The energy required to melt 1kg of a substance with no change in temp.

Question 16

What is the specific latent heat of vaporisation?

Answer 16

The energy required to evaporate 1kg of a substance with no change in temperature.

Question 17

What is specific latent heat measured in?

Answer 17

J/KG

Question 18

What does the temperature change depend upon when a substance is heated or cooled?

Answer 18

• The substance’s mass.
• The type of material.
• How much energy is transferred to it.

Question 19

How does a solid change to a liquid then a gas?

Answer 19

By melting then boiling/evaporation.

Question 20

How does a gas change to a liquid then a solid?

Answer 20

by condensation then freezing.

Question 21

How does a solid become a gas?

Answer 21

By sublimation.

Question 22

What is specific heat capacity?

Answer 22

The amount of energy needed to raise the temperature of 1kg of the substance by 1 degree.

Question 23

What are the particles in a gas constantly doing?

Answer 23

Moving in a random direction with random speeds.

Question 24

What happens when a gas is heated?

Answer 24

The particles gain kinetic energy and move faster, so the temperature of the gas increases.

Question 25

What is the pressure a gas exerts on a surface caused by?

Answer 25

The force of the gas particles hitting the surface.

Question 26

Why does the pressure increase if the temperature of a gas in a sealed container increases?

Answer 26

Because:

• The particles move faster so they hit the surfaces with more force.
• The number of these impacts per second increases, exerting more force overall.

Question 27

Why does the temperature increase if a gas is compressed too quickly?

Answer 27

Because:

• Compressing the gas requires a force to be applied to the gas - resulting in work being done to the force.
• The energy gained by the gas is not transferred quickly enough to its surroundings.