Separate Physics - 6.3

Question 1

How can the density of a material be calculated?

Answer 1

Question 2

What are the three states of matter?

Answer 2

• Solid
• Liquid
• Gas

Question 3

What affects the density of an object?

Answer 3

The material it is made of and how the particles are arranged

Question 4

Draw a model of the particle arrangement for a solid

Answer 4

Question 5

Draw a model of the particle arrangement for a liquid

Answer 5

Question 6

Draw a model of the particle arrangement for a gas

Answer 6

Question 7

What does the phrase: “a change of state conserves mass” mean?

Answer 7

When materials change state this is a physical change where the number of particles (and the mass) remains the same

Question 8

Describe the state changes

Answer 8

• Melting (solid → liquid)
• Freezing (liquid → solid)
• Sublimating (solid → gas)
• Boiling / evaporating (liquid → gas)
• Condensing (gas → liquid)

Question 9

What happens in a physical change of state to a material’s original properties?

Answer 9

The properties can be recovered if the change is reversed

Question 10

What is internal energy?

Answer 10

The energy stored by the particles which makes up a system

Question 11

How can internal energy be calculated?

Answer 11

It is the total kinetic energy and potential energy of all the particles that make up the system

Question 12

What happens to the internal energy of a system when heat is applied?

Answer 12

Heating the system transfers energy to the particles (gaining energy in their kinetic stores and moving faster) increasing the internal energy

Question 13

What is the specific heat capacity of a substance?

Answer 13

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

Question 14

What does a change of state require?

Answer 14

Energy

Question 15

What is specific latent heat?

Answer 15

The amount of energy needed to change 1kg of the substance’s state (without changing its temperature)

Question 16

What is specific latent heat of fusion?

Answer 16

A change of state from solid to liquid

Question 17

What is specific latent heat of vapourisation?

Answer 17

A change of state for liquid to vapour

Question 18

Draw a graphical representation and describe for a change of state involving temperature changes

Answer 18

Question 19

What is average energy in kinetic stores related to?

Answer 19

Temperature

Question 20

What happens to the particles of a gas when temperature is increased?

Answer 20

The average speed of the particles increases as the energy in the particles’ kinetic energy stores is ½mv²

Question 21

Explain what changing the temperature of a gas at constant volume causes

Answer 21

Increases the pressure as the particles move faster and hit the container walls more often

Question 22

What can a change in pressure cause?

Answer 22

A change in volume

Question 23

Why can work done cause a temperature increase in a gas?

Answer 23

Energy transferred by a force (work) transfers energy to the kinetic energy stores of the gas particles, increasing their temperature

Question 24

Separate Q. When a gas is compressed or expanded by pressure changes what does this cause?

Answer 24

The pressure produces a net force at right angles to the wall

Question 25

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

Answer 25

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

Question 26

Separate Higher Q. What is work?

Answer 26

The transfer of energy by a force

Question 27

Separate Higher Q. What does doing work cause to a gas?

Answer 27

It increases the internal energy and can cause an increase in the temperature

Question 28

Separate Higher Q. Explain why a bicycle pump doing work increases the temperature

Answer 28

The gas exerts a pressure (and force) and work has to be done against this, causing a transfer of energy to the kinetic energy stores (increasing the temperature)