Every substance in the Universe is made up from substances
called elements. Each element has different properties
and uses. They can be sorted into groups such as metals
and non-metals. At room temperature most are solids,
but some are liquids or gases.
Each element is made up of different types of atoms.
The periodic table shows
how differences between atoms affect the properties of the
elements. The atoms of different elements combine to make
new substances or compounds.