rubidium
/ruːˈbɪdɪəm/noun
mass noun
- the chemical element of atomic number 37, a rare soft silvery reactive metal of the alkali metal group. (Symbol: Rb)（化学元素）铷（符号： Rb）。
词源
mid 19th cent.: modern Latin, from Latin rubidus 'red' (with reference to its spectral lines).