Quantum mechanics (QM; also known as quantum physics or quantum theory) including quantum field theory, is a fundamental branch of physics concerned with processes involving, for example, atoms and photons.
Use oxide in a sentence. 1  a binary compound of oxygen with some other element or with a radical. 2  Divalent anionic oxygen, or a compound of oxygen, especially a binary compound of oxygen with a more electropositive element. Origin of oxide. French ox(ygÃ¨ne) oxygen ; see oxygen . (ac)ide acid ( from Latin acidus tart, acid ; see acid .
Iron oxide is any one of a range of chemical compounds made up of iron and oxygen. Most of these are naturally occurring; some form in the soil or in chemical deposits in rocks or mountains, and rust is also a very common and well-known source. Not all oxides are useful to humans, but several varieties play key roles in industry, cosmetics, and art.