Elements, compounds and mixtures

An element is a pure substance which cannot be split into simpler substances by any chemical process.

May consist of individual atoms e.g. copper (Cu) Or molecules composed of atoms of the same kind, e.g. oxygen (O2)

There are 103 different elements; they can be divided into metals and non-metals

A compound is a substance containing two or more different types of element bonded together chemically in fixed proportions and in such a way that their properties are changed.

For example: magnesium + oxygen  $\rightarrow$  magnesium oxide

 Other examples include: water (H2O), carbon dioxide (CO2)

A mixture consists of two or more substances (elements and /or compounds).

Each component in the mixture t\retains their independent properties because they did not undergo any chemical reaction.

For example: sand & water, salt & pepper

sugar & water, salt & water

Research the different separation techniques used in chemistry

Select three (3) techniques and list one mixture that can be separated by each technique.