Introductory Chemistry Year 8

This is because the heat causes the particles to vibrate more, as they do, they need more space, thus the material made up of the particles expands.
Sometimes the expansion can cause the substance to go into liquid state.
Upon further heating, the attraction between the particles breaks down, and the substance becomes a gas

-are reversible
-usually involve a change of state
-can involve temperature changes like the addition of heat
-can involve the addition of a solvent, in which case the substance dissolves, becoming a solute in a solution

​Produce new substances!!!

A chemical change has taken place IF one or more of the following is produced
-heat -gas -a solid (precipitate)
-light -colour change
-sound -temperature change

​Rearrange atoms- the building blocks of matter

All matter is made up of atoms.
When different atoms combine, they become compounds
All known atoms have been arranged into a Periodic Table, first put together by Dmitri Mendeleev