Californium

Physical & atomic properties

Atomic number

98

Atomic mass (u)

251.07959

Category

Actinide

Standard state

Solid

Melting point

899.85 °C (1173 K)

Boiling point

Not reported

Density (g/cm³)

Not reported in this source

Electronegativity (Pauling)

1.3

Electron configuration

[Rn]7s2 5f10

Oxidation states

+3

Atomic radius (pm)

245

First ionization energy (eV)

6.30

Discovery & recognition

Discovery year / period (PubChem)

1950

Discovery credited to (RSC)

Stanley Thompson, Kenneth Street, Jr., Albert Ghiorso, and Glenn Seaborg

Date or period recorded by RSC

1950

Discovery place

Berkeley, California, United States

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

Natural occurrence & production

This transuranium element is primarily produced through nuclear reactions in reactors or particle accelerators. Some transuranium elements also occur naturally in extremely small traces; that is different from a mineable deposit.

“Californium did not exist in weighable amounts until ten years after its discovery.”

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.