Particle Model Of Matter (P1)

Question 1

Density

Answer 1

Mass in kg/volume in m3

Question 2

Solids

Answer 2

Strong forces of attraction hold the particles close together in a fixed, regular arrangement. The particles don’t have much energy so they can only vibrate about their fixed positions. The density is generally highest in this state as the particles are closest together

Question 3

Liquids

Answer 3

There are weaker forces of attraction between the particles. The particles are close together, but can move past each other and form irregular arrangements. They have more energy than the particles in a solid- they move in random directions at low speeds. Liquids are generally less dense than solids

Question 4

Gases

Answer 4

There are almost no forces of attraction between the particles. The particles have more energy than in liquids and solids- they’re free to move, and travel in random directions at high speeds. Gases are generally less dense than liquids.

Question 5

Internal energy

Answer 5

The energy stored by the particles that make up a system. Kinetic and potential energy stores
Heating transfers to the particles
Leads to a temp or state change
Change in state is if there is enough kinetic energy in the stores to break the bonds

Question 6

State changes

Answer 6

Lose or gain energy and form or break bonds
Physical change (same substance)
Can reverse 
No change in number of particles, arrangement changes

Question 7

A change of state requires

Answer 7

Energy, when a state change happens the temp doesn’t change as energy is transferred

Question 8

Specific latent heat

Answer 8

The SLH is the energy needed to change the state of 1kg of a substance without a temperature change
For cooling it is the energy released
Different for different materials
Solid and liquid is the SLH of fusion
Liquid and gas is the SLH of vaporisation

Question 9

SLH formula

Answer 9

Energy = mass x SLH

E=mL

Question 10

How is pressure created?

Answer 10

Colliding gas particles
In a sealed container it is with the walls
pressure and volume and inversely proportional

Question 11

Change in pressure causes

Answer 11

A change in volume
Pressure causes a net outward force at right angles to container
Force on the outside due to gas pressure around
If container can easily change size it will compress or expand

Question 12

Doing work

Answer 12

If you transfer energy by applying a force

Question 13

Doing work on a gas

Answer 13

Increases the internal energy which can increase the temperature
Doing work mechanically e.g. bike pump applies pressure to plunger and exerts a force on it, work has to be done against the force
Transfers energy to kinetic energy stores of the particles increases temp

Question 14

Doing work mechanically

Answer 14

Doing work mechanically e.g. bike pump applies pressure to plunger and exerts a force on it, work has to be done against the force
Transfers energy to kinetic energy stores of the particles increases temp

Question 15

Temperature

Answer 15

The average kinetic energy of the particles