Changes of state and internal energy: Matter: Physics: GCSE (9:1)

State of matter

A physical property that describes matter as a solid, liquid, or gas

Change of state

A physical change of a substance from one state of matter to another

Melting

The change of state from a solid to a liquid

Boiling

Change of state from a liquid to a gas (occurs at a fixed temperature known as the boiling point)

Evaporating

Change of state from a liquid to a gas (that occurs at at the surface of a liquid below it's boiling point)

Condensing

Change of state from a gas to a liquid

Sublimation

The change of state from a solid to a gas (or a gas to a solid)

Freezing

The change of state from a liquid to a solid

Melting point

The temperature at which a solid becomes a liquid (when being heated) or a liquid becomes a solid (when being cooled)

Boiling point

The temperature at which a liquid becomes a gas (when being heated) or a gas becomes a liquid (when being cooled)

Physical change

When a substance recovers its original properties if the change is reversed

Conservation of mass

Mass cannot be created or destroyed during a physical or chemical change

Internal energy

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

The energy change when a substance is heated or cooled

The internal energy of the particles increases or decreases

The energy change when a substance's temperature changes

The kinetic energy of the the particles increases or decreases

The energy change when a substance changes state

The particles are gain or lose potential energy because bonds between them break or form