Separate Physics - P3 Particle Model of Matter

Question 1

What equation links density, mass and volume?

Answer 1

Density = mass / volume

⍴ = m / v

Question 2

What two energy stores make up the internal energy stored by particles?

Answer 2

Kinetic energy and potential energy stores.

Question 3

Draw a particle model for a liquid.

Answer 3

Question 4

Name the change of state when a solid turns straight into a gas.

Answer 4

Sublimation

Question 5

Draw a particle model for a solid.

Answer 5

Question 6

Draw a particle model for a gas.

Answer 6

Question 7

Name the changes of state labelled a, b, c and d.

Answer 7

a) Melting
b) Freezing
c) Boiling
d) Condensing

Question 8

What is specific latent heat of vaporisation?

Answer 8

The energy needed to change the state of a substance between a liquid and gas (boiling or condensing).

Question 9

Why is there not a temperature rise during a change of state?

Answer 9

• Energy is put into the system.
• The internal energy of the system increases.
• But the energy is used to break bonds rather than raising the temperature of the system.

Question 10

What is specific heat capacity?

Answer 10

The amount of energy required to raise the temperature of 1 kg of the substance by 1 ^oC.

Question 11

What is specific latent heat?

Answer 11

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

Question 12

What is the name for the energy stored by particles?

Answer 12

Internal energy

Question 13

What happens to the internal energy of a system when heated?

Answer 13

• Particles gain energy
• Kinetic energy store of particles increases
• Particles move faster
• Internal energy increases

Question 14

What happens when you increase the temperature of a gas at constant volume?

Answer 14

• Increases the pressure
• Because the particles move faster
• Increased frequency of collisions of particles with the sides of the container.

Question 15

What is specific latent heat of fusion?

Answer 15

The energy needed to change the state of a substance between a solid and liquid (melting or freezing).

Question 16

What are the units for:

a) Mass
b) Volume
c) Density

Answer 16

a) The units for mass are kg
b) The units for volume are m³
c) The units for density are kg/m³

Question 17

How would you measure the density of a regular object?

Answer 17

• Measure the volume of the object (e.g. for a square, you would measure the length of the sides using a ruler and multiply length x width x height)
• Measure its mass using a balance.
• Calculate density using the equation: density = mass / volume

Question 18

How would you measure the density of a liquid?

Answer 18

• Use a measuring cylinder to measure the volume of a liquid.
• Use a balance to measure the mass of a liquid.
• Calculate density using the equation: density = mass / volume

Question 19

What do the horizontal lines on a heating or cooling curve represent?

Answer 19

A change of state

Question 20

How would you measure the density of an irregular object?

Answer 20

• Measure the mass using a balance.
• Measure volume by placing the object in a eureka can filled with water.
• Measure the volume of water displaced into a measuring cylinder to find the volume of the object.
• Calculate density using the equation: density = mass / volume

Question 21

Separate Q. What are the SI units for:

a) Pressure
b) Temperature

Answer 21

a) The units for pressure are pascals (Pa)
b) The units for temperature are ^oC

Question 22

Separate Q. Describe what causes gas pressure in a sealed container.

Answer 22

• Gas particles collide with the sides of the container.
• With each collision, they exert a force on the container.
• The outward pressure is the total force of all the particles exerted over the area of container walls.

Question 23

Separate Q. Describe the relationship between pressure and volume.

Answer 23

• Pressure and volume are inversely proportional.
• As volume increases, pressure decreases.
• As volume decreases, pressure increases.

Question 24

Separate Q. Why does increasing the volume in which a gas is contained, at constant temperature, decrease the pressure?

Answer 24

Increasing the volume spreads the particles out so they hit the container less often, decreasing the pressure.

Question 25

Separate Higher Q. What effect does ‘doing work’ on a gas cause?

Answer 25

• An increases in internal energy.
• An increase in temperature.

Question 26

Separate Q. When particles collide with the surface of a container, at what angle is the force exerted?

Answer 26

At right angles to the surface of the container.

Question 27

Separate Higher Q. Give the definition of ‘work’.

Answer 27

The transfer of energy by a force

Question 28

Separate Higher Q. Explain why a bike tyre gets warmer as you pump it up.

Answer 28

• The gas particles apply pressure on the pump and therefore exerts a forces against the pump.
• You have to ‘do work’ against the force in order to push down the pump and push air into the tyre.
• By ‘doing work’, you transfer energy to the kinetic energy stores of the gas particles.
• The temperature increases, so the bike tyre will feel warmer.