Ununpentium

Part of speech: noun

Definitions

1. A highly unstable superheavy chemical element with 115 protons in its nucleus, created artificially in particle accelerators and existing only for fractions of a second
2. An artificially produced transuranic element designated by the atomic number 115, synthesized in laboratories and belonging to the pnictogens group on the periodic table
3. A synthetic element with atomic number 115 that was officially named nihonium in 2016, produced through nuclear fusion reactions and too unstable to occur naturally

Etymology: Ununpentium works like a phone number. Before a new element received a permanent name, chemists labelled it with a systematic name built from the digits of its atomic number, one numeral per digit, with "-ium" added as the ending for a new element. Read as un-un-pent, the parts give 115, the element's place in the periodic table. These temporary names were a stopgap. The numerals come from Latin and Greek: "un" from Latin "unus" for one, and "pent" from Greek "pente" for five. Once the discovery was confirmed, the element's discoverers proposed a permanent name, and the International Union of Pure and Applied Chemistry approved it. Element 115 became moscovium, named after the Moscow region where the work was carried out, and the placeholder was retired.

Synonyms: element 115, moscovium