
A chemical element, often simply called an element, is a type of atom which has the same number of protons in its atomic nucleus (i.e., the same atomic number, or Z ). This database focuses on the most common chemical compounds used in the home and industry. This is a list of the 118 chemical elements that have been identified as of 2023.

Molar mass calculations are explained and there is a JavaScript calculator to aid calculations. Oxygen is a highly reactive nonmetallic element and forms compounds with most elements except the noble gases Helium and Neon.

Oxygen is a colourless, odourless, tasteless gas essential to living organisms, being taken up by animals, which convert it to carbon dioxide plants, in turn, utilize carbon dioxide as a source of carbon and return the oxygen to the atmosphere. Skip to site menu on this page Periodic Table of Elements O - Oxygen Oxygen Menu oxygen (O), nonmetallic chemical element of Group 16 (VIa, or the oxygen group) of the periodic table.
