Particle movement

Question 1

Particles in a solid

Answer 1

Very close together
Arranged in a regular pattern
Vibrate but don’t move

Question 2

Particles in a liquid

Answer 2

Close together
Not arranged in a regular pattern
Can move around each other

Question 3

Particles in a gas

Answer 3

Far apart
Not arranged in any pattern
Move very rapidly

Question 4

Density

Answer 4

Tells us the mass for a given volume

Question 5

High density

Answer 5

A high mass packed into a smaller volume
Eg a very heavy small thing like a brick

Question 6

Low density

Answer 6

Lower mass packed into a higher volume
Eg a very light big thing like a tissue

Question 7

Density equation

Answer 7

= mass(kg)
—————
Volume (m3)

Question 8

Density unit

Answer 8

Kg/m3

Question 9

What density do solids have?

Answer 9

A high density
Because they have lots of particles packed in its volume since they don’t move around

Question 10

What density do liquids have?

Answer 10

Usually high
Because like solids they have particles close together in a volume

Question 11

What density do gases have?

Answer 11

Low density
Because the particles are far apart = small mass for their volume

Question 12

Polystyrene

Answer 12

A solid yet has a low density
Because it has an open structure with many air spaces

Question 13

Why do all states have kinetic energy?

Answer 13

Because their particles are either moving or vibrating around each other = movement

Question 14

Potential energy

Answer 14

The energy between particles as intermolecular forces or chemical bonds

Question 15

Internal energy

Answer 15

The energy caused by both potential energy AND kinetic energy
Total energy stored inside particles of the system

Question 16

How do we change state?

Answer 16

Increase its internal energy until it reaches its melting or boiling point = changed state

Question 17

Melting

Answer 17

Solid to liquid
After increasing temperature
Increases internal energy

Question 18

Boiling

Answer 18

Liquid to gas
After increasing temperature
Increases internal energy

Question 19

Condensation

Answer 19

Gas to liquid
After decreasing temperature
Reduces internal energy

Question 20

Freezing

Answer 20

Liquid to solid
After decreasing temperature
Reduces internal energy

Question 21

Sublimation

Answer 21

Solid to gas
By increasing temperature

Question 22

What happens to mass when we change state?

Answer 22

DOESN’T CHANGE because conserved

Question 23

What type of change is changing state?

Answer 23

Physical so we can reverse it back to its original state

Question 24

If you change state by cooling how does it affect mass?

Answer 24

It doesn’t
The volume will decrease but the density is increased

Question 25

If you change the state by heating how does it affect mass?

Answer 25

It doesn’t

Question 26

On a heating graph what does the straight line represent?

Answer 26

The material is changing state But not changing in temperature Because the energy taken in is weakening/breaking the forces of attraction to change state

Question 27

When we change state do we change the temperature of the material?

Answer 27

No because the energy taken is is used to break/make forces of attraction

Question 28

Melting point

Answer 28

The temperature a substance melts at

Question 29

Boiling point

Answer 29

The temperature a substance boils at

Question 30

Cooling graph

Answer 30

Shows the temperature a substance follows as it decreases in temperature

Question 31

Specific latent heat

Answer 31

The amount of energy required to change state of 1kg of the substance with no change in temperature (because the temperature is used to break the bond)

Question 32

Specific latent heat of fusion

Answer 32

Energy required to change 1kg of substance to solid —> liquid with no change in temperature

Question 33

Specific latent heat of vaporisation

Answer 33

Energy required to change 1kg of a substance from a liquid to a vapour with no change in temperature

Question 34

Energy for a change of state

Answer 34

Mass(kg) x specific latent heat (J/kg)

Question 35

What is specific latent heat measured in?

Answer 35

J/kg

Question 36

When calculating specific latent heat what is the mass measured in?

Answer 36

Kg

Question 37

Pressure of a gas

Answer 37

Due to particles colliding with walls of the container

Question 38

Pressure of a gas

Answer 38

Due to particles colliding with walls of the container

Question 39

What increases the pressure of a gas?

Answer 39

Increase the number of collisions per second Increase the energy of each collision

Question 40

How can we actively increase the pressure of a gas?

Answer 40

Increase the temperature

Question 41

How does increasing the temperature increase the pressure?

Answer 41

At low temperature particles have low kinetic energy So fewer collisions per second as well as low energy collisions But at high temperatures = particles have higher kinetic energy so more high energy collisions per second

Question 42

What is the force in a gas container like?

Answer 42

Acts at right angles to the container over its area

Question 43

What does increasing the volume do to the gas?

Answer 43

Decrease the pressure because the particles have to travel further before colliding with walls So less collisions per second = lower pressure

Question 44

Relationship between pressure and volume of a gas

Answer 44

They are inversely proportional Increasing volume = decrease pressure

Question 45

Gas pressure equation

Answer 45

pressure (Pa) x volume (m3) = constant ONLY if temperature is constant

Question 46

Force applied on a container with a gas in it

Answer 46

We have done work, (transferring energy by a force) So energy transferred to particles Increases internal energy Increases temperature of the gas

Question 47

Why do bicycle pumps increase in temperature?

Answer 47

Work applied to container Gas particles have energy transferred to them Increases their internal energy Increases temperature