Seleniums

Part of speech: noun

Definitions

1. A group of chemical elements related to sulfur, often found in minerals and used in various industrial applications
2. The plural form of a non-metallic element used in electronic components and glass production
3. Multiple instances of an essential trace element that plays a role in metabolism and antioxidant defense in living organisms

Etymology: Selenium was named by Jöns Jacob Berzelius, the Swedish chemist, in 1818, and the name was chosen to point to the element tellurium. Berzelius had found the new substance in residues from sulphuric acid production and initially mistook it for tellurium, which was already known. The name comes from Ancient Greek "selēnē", meaning "moon", a deliberate pairing with tellurium, whose name derives from Latin "tellus", meaning "earth". Seleniums is simply the plural of selenium, used when referring to more than one such element. Because the word is a formal chemical coinage, its plural is rarely needed in practice, since chemists normally speak of the element as a single kind of substance.