Chemists use symbols and formulae to represent elements, ions and compounds. Word equations and balanced chemical equations model the changes that happen in chemical reactions.
Each element is represented by its own chemical symbol. A chemical symbol:
For example, the element mercury is shown as Hg. Do not show it as HG, hg or hG.
The periodic table shows the names and symbols of the elements. Elements are arranged into groups that share similar characteristics. Groups are numbered from 1 to 7, then 0. Metals are found on the left and non-metals are found on the right.