Radium

Atomic number

88

Atomic mass (u)

226.02541

Category

Alkaline earth metal

Standard state

Solid

Melting point

699.85 °C (973 K)

Boiling point

1139.85 °C (1413 K)

Density (g/cm³)

5

Electronegativity (Pauling)

0.9

Electron configuration

[Rn]7s2

Oxidation states

+2

Atomic radius (pm)

283

First ionization energy (eV)

5.279

Discovery & recognition

Discovery year / period (PubChem)

1898

Discovery credited to (RSC)

Pierre and Marie Curie

Date or period recorded by RSC

1898

Discovery place

Not supplied in the structured record; see the RSC history source.

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.

“Radium is present in all uranium ores, and could be extracted as a by-product of uranium refining.”

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.