atomic number 5

Thesaurus

Noun

1.

atomic number 5 - a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powderboron, Bchemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matterborax - an ore of boron consisting of hydrated sodium borate; used as a flux or cleansing agentkernite - a light soft mineral consisting of hydrated sodium borate in crystalline form; an important source of boron