Particle model of matter

Question 1

density equation

Answer 1

density = mass / volume

Question 2

density of solids and liquids

Answer 2

similar densities as the space between the particles do not change significantly

Question 3

density of gases

Answer 3

the spacing between atoms increase x10 as the paticles have lots of energy to move so volume increases and therefore density increases

Question 4

what happens to mass during change of state

Answer 4

stays the same

Question 5

whats it called when something goes from solid straight to gas

Answer 5

sublimation

Question 6

1. what is internal energy
2. the two forms

Answer 6

1. energy which is stored by particles within a system
2. kinetic and potential

Question 7

1. specific heat capacity def
2. equation

Answer 7

1. the amount of energy required to raise the temp of 1kg of a substance by 1°C
2. change in thermal energy = mass x specific heat capacity x temp change

Question 8

1. specific latent heat def
2. equation

Answer 8

1. the amount of energy required to change the state of 1kg of a substance without a change in temp
2. energy required = mass x specific latent heat

Question 9

specific latent heat of fusion
specific latent heat of vaporisation

Answer 9

energy to melt/freeze
energy to boil/condense

Question 10

energy is absorbed when…
energy is released when…

Answer 10

…melting or evaporating
…freezing or condensing

Question 11

explain pressure

Answer 11

1. the molecules of a gas are in constant random motion
2. when the molecules collide with the walls of the container or each other they exert a force
3. as the temp is raised, the kinetic energy of the molecules increases, making them speed up
4. therefore they collide with the walls of the container and each other more frequently, increasing the pressure

Question 12

boyle’s law

Answer 12

increasing the volume in which a gas is contained, can lead to a decrease in pressure

Question 13

P1V1 = constant
therefore…

Answer 13

…increasing the volume of a container with lead to a decrease in pressure

Question 14

increasing pressure of a gas equation

Answer 14

work done = pressure x volume
OR
work done = force/area x (area x distance)
OR
work done = force x distance

Question 15

what does ‘doing work on a gas’ mean?

Answer 15

compressing or expanding the gas (changing the volume)

Question 16

what happens to temp when more gas is added to a fixed volume?

Answer 16

energy is transferred to the particles when more gas is added into the fixed volume , so this heats the gas

Question 17

unit for pressure

Answer 17

pascals