Heating And Changes Of State - State Of Matter

Question 1

Susbtances can change from one state to another
Solid to liquid to gas

Answer 1

When a solid is heated , particles gain energy and move.
Some of forces break.
At melting point, the particles have the energy to break free from positions - melting - liquid
When a liquid is heated, particles gain more energy
Forces holding liquids together weaken and break.
At boiling point, particles have enough energy to break forces - boiling - gas

Question 2

Substances changing state
Gas - liquid - solid

Answer 2

Gas cools, particles have less energy.
Forces form between particles.
At boiling point, forces between particles are strong enough gas becomes a liquid - condensing.
When a liquid cools, particles have less energy.
Forces become stronger
At melting point, forces between particles are so stront theyre held in place. Liquid becomes a solid - freezing,

Question 3

How to predict state of a substance

Answer 3

Below melting point = solid
Above boiling point = gas
Inbetween = liquid