AQA Physics Particle Model of Matter NEW GCSE

Solid

The state of matter where the particles are linked by strong forces. They are packed closely together and move very little. The particles usually form a regular and specific pattern.

Liquid

The state of matter where the particles have weaker bonds. They are still tightly packed but may move around each other.

Gas

The state of matter where particles are far apart and are in constant random motion. There is no interactive between the particles.

Melting Point

The temperature at which a solid turns into a liquid .

Boiling Point

The temperature at which a liquid turns into a gas.

Melting

When a solid changes to a liquid.

Boiling

When a liquid changes a gas at the boiling point

Evaporating

When a liquid changes to a gas below the boiling point

Condensing

When a gas changes to a liquid.

Internal Energy

The total energy in the kinetic and potential stores of all the particles (atoms and molecules) that make up a system.

Specific Heat Capacity

The amount of energy required to raise the temperature of one kilogram of a substance by one degree Celsius. Often represented by the symbol 'c'. Its unit it J/kg°C.

Specific Latent Heat

The amount of energy required to change the state of one kilogram of the substance with no change in temperature. Often represented by 'L'. Its unit is J/kg..

Gas pressure

When molecules collide with the wall of their container they exert a force on the wall. The total force exerted by all of the molecules inside the container on a unit of area of the wall is the gas pressure.

Volume

The amount of space that a substance or object occupies, or that is enclosed within a container. Often represented by 'V'.

Metres cubed (m³)

The unit of volume.

Density

The mass per unit volume of a material. It can be thought of as representing how tightly packed the particles are within the material. Often represented by 'ρ'. The unit of density is kg/m³.

kg/m³

The standard unit of density.

Sublimation

When a solid changes into a gas when it is heated without becoming a liquid first.

Specific Latent Heat Of Fusion

The amount of energy required to change one kilogram of a solid into a liquid with no change of temperature.

Specific Latent Heat Of Vaporisation

The amount of energy required to change one kilogram of a liquid into a gas (vapour) with no change of temperature.

Heating Curve

A graph which shows how the temperature of a substance changes as it is heated.

Cooling Curve

A graph which shows how the temperature of a substance changes as it is cooled.

Random/Brownian Motion

The unpredictable path that an individual gas particle follows.

Pascals (Pa)

The unit of pressure.

Formula to calculate specific heat capacity

∆E = m x c x ∆θ

Formula to calculate specific latent heat

E = m x L

Formula to calculate density

p = m / V