P3

Question 1

Density formula

Answer 1

Density = mass (kg)
————–
Volume (m*3)

Question 2

What can the particle model be used to explain (hint - 2 things)

Answer 2

• the different states of matter
• differences in density.

Question 3

What are changes of state and how are they different from chemical changes

Answer 3

Changes of state are physical changes which differ from chemical changes because the material recovers its original properties if the change is reversed.

Question 4

What is internal energy

Answer 4

Internal energy is the energy stored in a system by the atoms and molecules that make up that system

Question 5

How does heating affect internal energy

Answer 5

Heating changes the energy stored within the system by increasing the energy of the particles that make up the system. This either raises the temperature of the system or produces a change of state.

Question 6

How do you calculate change in thermal energy (hint - __x__x__)

Answer 6

Energy = mass x specific heat capacity x temperature change

Question 7

What is specific heat capacity

Answer 7

The amount of energy needed to heat 1 kg of a substance by 1* Celsius

Question 8

Note - Remember if questions involve change in state and ask for new volume/pressure, the mass is the same!

Answer 8

Note - Remember if questions involve change in state and ask for new volume/pressure, the mass is the same!

Question 9

What does heating a system do

Answer 9

• Heating increases the energy the particles have
• This increases the internal energy
  -This either raises the temperature of the system
  -Or produces a change of state

Question 10

What is specific latent heat

Answer 10

• The amount of energy needed to change the state of 1kg of a substance without a change in temperature

Question 11

density of water

Answer 11

1000kg/m*3

Question 12

density of glass

Answer 12

3140kg/m*3

Question 13

density of iron

Answer 13

7700kg/m*3

Question 14

density of aluminium

Answer 14

2800kg/m*3

Question 15

density of hydrogen

Answer 15

0.085kg/m*3

Question 16

what happens to mass and volume during change of state

Answer 16

Mass is conserved when a substance changes state, only the volume changes

Question 17

what is internal energy made up of

Answer 17

The total kinetic (Ek) and potential (Ep) energy in the system make up the internal energy (U).

Question 18

describe the motion of particles in a liquid or gas

Answer 18

The particles inside a liquid or a gas
are in constant motion, colliding
with each other and the walls of any
container they are in.

Question 19

describe the motion of particles in a solid

Answer 19

In a solid the particles are vibrating
around a fixed point.

Question 20

what happens when heat is added to a system? what could this result in?

Answer 20

When heat is added to a system the internal energy of the particles increases. This can result in the material changing state.

Question 21

what are the two types of latent heat

Answer 21

latent heat for melting is called specific latent heat of fusion (Lf)

Latent heat for evaporating is called specific latent heat ofvaporisation

Question 22

what is specific latent heat of fusion

Answer 22

latent heat for melting is called specific latent heat of fusion (Lf)

Question 23

what is specific latent heat of vapourisation

Answer 23

Latent heat for evaporating is called specific latent heat of vaporisation

Question 24

what is specific latent heat for melting called

Answer 24

specific latent heat of fusion

Question 25

what is specific latent heat for evaporation called

Answer 25

specific latent heat of vapourisation

Question 26

how do you calculate energy to change state

Answer 26

Energy to change state (J) = mass (kg) x specific latent heat (J/kg)

Question 27

draw a heating and cooling graph

Answer 27

check favourited photos

Question 28

describe particle motion in gas

Answer 28

Molecules in a gas are in constant random motion (called Brownian motion)

Question 29

points in a 4 mark question about particle motion in gas

Answer 29

The temperature of this gas is related to
the average kinetic energy of all the
particles.

• If the temperature of the gas is increased,
  the particles will move faster.
• Faster moving particles exert a greater
  force on the walls of the container.
• This will either cause the container to
  expand (balloon) or increase the pressure
  of the gas (gas cylinder).

Question 30

what is the relationship between gas pressure and temperature

Answer 30

inverse proportion

Question 31

what are the 2 formulas for pressure and temperature in a gas (hint - inverse proportion)

Answer 31

pV = constant

and

For calculations:
p1V1 = p2V2

Question 32

describe the particle arrangement in a gas in contrast to solid or liquid

Answer 32

In gases the particles take up
a much greater volume than in
liquids and solids.

Question 33

describe the particle arrangement in liquids in contrast to solids

Answer 33

In liquids the particles are free
to move so the same mass
takes up more space.

Question 34

describe the particle arrangement in solids

Answer 34

in solids the particles are
packed close together

Question 35

how is the arrangement of particles in a dense material different to a less dense material

Answer 35

a dense material has its particles packed closely together and a less dens material has its particles more spread out