Chemists use symbols and formulae to represent elements and compounds. Word equations and balanced chemical equations represent the changes that happen in chemical reactions. Mixtures - AQA There are ...

Periods and families in the periodic table are described. Organization of the Periodic Table: Periods and families in the periodic table are described. Students learn to determine the number of energy ...

Players read questions about energy levels and score points by picking the correct element as the answer. Electrons are in regions around the nucleus that are different distances away from the nucleus ...

The covalent radius (a measure of how large individual atoms are) shows different trends if you are moving across a period or down a group. A comparison of the relative covalent radii of atoms is ...