rubidium

/ˌɹuːˈbɪd.i.əm/

ɹUːBꞮD · i · əm (3 syllables)

English Noun

Definition

The chemical element (symbol Rb) with an atomic number of 37. It is a soft, highly reactive alkali metal.

Etymology

A New Latin word derived by German chemist R. W. Bunsen in 1861, from Latin rūbidus (“red”) because its spectrum has two red lines.