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 ...

Neutral Calcium (Ca): 20 protons and 20 electrons. Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s². Calcium Ion (Ca²⁺): 20 ...

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 ...

Measurements of an artificial radioactive element called lawrencium could revive an arcane controversy over the element’s position in the periodic table — and the structure of the table itself. An ...

Chemistry teachers recently had to update their classroom décor, with the announcement that scientists have confirmed the discovery of four new elements on the periodic table. The as-yet unnamed ...