Trihydride

Part of speech: noun

Definitions

1. A chemical substance composed of a molecule containing three hydrogen atoms bonded to another element or group
2. A compound that includes three hydrogen atoms combined with one or more other elements in its molecular structure
3. A molecular entity characterized by the presence of three hydrogen atoms covalently attached to a central atom or molecular fragment

Etymology: Chemists needed a name for molecules carrying three hydrogens, and they built it from a prefix and a word that had already been put to work for compounds containing hydrogen. The "hydr-" element comes from Ancient Greek "hudōr," meaning water, and it reached English through the combining form "hydro-," which turned up in terms like hydrogen, a name coined because the gas forms water when burned. The "-ide" ending, borrowed through Latin "-idus" and French, is the familiar chemical suffix used for binary compounds, so "hydride" names a compound of hydrogen with another element. "Tri-" is the Latin-derived prefix for three, so a trihydride is simply a hydride with three hydrogen atoms bound to a central atom or fragment. The construction is systematic rather than traditional: the name describes the structure directly, as chemical nomenclature generally does, instead of inheriting an older common name. Its meaning follows the chemical terms it is built from, with no shift of sense from earlier usage.

Synonyms: metal hydride, chemical compound