Rubidium

Atomic number

37

Atomic mass (u)

85.468

Category

Alkali metal

Standard state

Solid

Melting point

39.31 °C (312.46 K)

Boiling point

687.85 °C (961 K)

Density (g/cm³)

1.53

Electronegativity (Pauling)

0.82

Electron configuration

[Kr]5s1

Oxidation states

+1

Atomic radius (pm)

303

First ionization energy (eV)

4.177

Discovery & recognition

Discovery year / period (PubChem)

1861

Discovery credited to (RSC)

Gustav Kirchhoff and Robert Bunsen

Date or period recorded by RSC

1861

Discovery place

Heidelberg, Germany

An ancient date does not identify a first human discovery. Different references may date observation, isolation and formal recognition differently.

Natural occurrence & production

The creation of an element’s nuclei and its concentration into terrestrial deposits are different processes. The occurrence note below concerns its presence or production on Earth; it is not a complete account of nucleosynthesis.

“Rubidium occurs in the minerals pollucite, carnallite, leucite and lepidolite.”

Royal Society of Chemistry · occurrence excerpt ↗

Continue the research

Reference values are not product specifications. Blank values have not been estimated. For superheavy elements, some properties and family assignments are theoretical or incompletely measured.