P1-Topic 3- Particle model of matter 2022

Question 1

What is the definition of density?

State the relevant equation with units

Answer 1

● The mass per unit volume of a material
● ⍴=m/v
● Density (kg/m³), Mass (kg), Volume (m³)

Question 2

State the different states of matter in order (least to

most) of density of atoms

Answer 2

● Least dense: Gas
● Liquid
● Most dense: Solid

Question 3

Describe the particle arrangement of a solid.

2

Answer 3

Tightly packed in a regular arrangement.

Particles can only vibrate on the spot

Question 4

Describe the particle arrangement of a liquid 2

Answer 4

Close together, but with an irregular arrangement.
They can flow over each
other

Question 5

Describe the particle arrangement of a gas.2

Answer 5

Separated, with no regular arrangement.

Particles can move freely

Question 6

What is always conserved when a substance undergoes a change of state?

Answer 6

Mass

Question 7

How does a change of state differ from a chemical change? 2

Answer 7

In a change of state, the material can return to having its previous properties if the change is reversed

-this means that changes of state are physical changes not chemical

Question 8

What is sublimation?

Answer 8

When a solid changes into a gas without passing through a liquid state

Question 9

What is evaporation?

Answer 9

When a liquid changes into a gas state

Question 10

When water boils in an open pan, why does the mass of the pan of water appear to decrease?

Answer 10

Some of the water will evaporate and turn
into water vapour.

This will leave the pan
meaning the mass of the pan will decrease.

The mass of the whole system however
remains constant.

Question 11

Explain the processes involved when a bathroom mirror mists up

Answer 11

● Hot water evaporates to form water vapour

● This water vapour lands on the cooler mirror

● The vapour condenses and returns to liquid
state on the mirror’s surface

Question 12

What is the internal energy of a substance?2

Answer 12

● The energy stored by the particles

● The sum of the total kinetic and potential energies that make up the system

Question 13

How does heating affect the energy of a substance?

Answer 13

● Heating transfers energy to the substance

● It increases the energy of the particles that make up the substance

Question 14

What two things can heating a substance

do?

Answer 14

1. Raise its temperature

2. Change the state of the substance

Question 15

What three factors determine the temperature change of a system?

Answer 15

1. Mass of substance being heated
2. Type of material (Specific heat
   capacity)
3. Energy inputted into the system

Question 16

State the equation used to calculate the
temperature change when a substance
is heated. Give appropriate units.

Answer 16

● ΔE = m c Δ𝛉
● Energy (J), Mass (kg), Specific Heat
Capacity (J/kg/°C), Temperature (°C)

Question 17

Define specific heat capacity.

Answer 17

The amount of energy needed to
increase the temperature of 1kg of a
substance by 1°C

Question 18

Describe how the internal energy and
temperature of a substance changes
when a change of state occurs 2

Answer 18

● The internal energy of the substance
will be increased or decreased

● The temperature of the substance will
remain constant

Question 19

Define specific latent heat

Answer 19

The amount of energy needed to change
the state of 1kg of a substance with no
change in temperature

Question 20

State the equation for the energy
required to change state. Give
appropriate units.

Answer 20

energy for a change of state = mass × specific latent heat
E = m L
energy, E, in joules, J
mass, m, in kilograms, kg
specific latent heat, L, in joules per kilogram, J/kg

Question 21

What is the specific latent heat of fusion?

Answer 21

The energy required to change 1kg of a
substance from solid state to liquid state
without a change in temperature.

Question 22

What is the specific latent heat of

vaporisation?

Answer 22

The energy required to change 1kg of a
substance from liquid state to gas state
(vapour) without a change in
temperature.