Discover the history, structure, and importance of the periodic table of elements, from Mendeleev’s discovery to modern scientific applications. When you purchase through links on our site, we may ...

Learn all about the 118 combinations of protons, neutrons and electrons that make up our world. Whether hung on classroom walls, put up in dorm rooms or screen-printed on T-shirts, the periodic table ...

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 ...

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 ...