98 Cf 251

Californium

Actinide

Californium (Cf) is a chemical element with atomic number 98, classified as a actinide. At room temperature it is a solid. It was discovered in 1950 by Glenn T. Seaborg et al..

Properties

Atomic number
98
Atomic mass
251 u
Category
Actinide
Group
0
Period
7
Block
f-block
Electron configuration
[Rn] 5f¹⁰ 7s²
Phase at STP
Solid
Density
15.1 g/cm³
Melting point
1173 K (899.9 °C)
Boiling point
1743 K (1469.8 °C)
Electronegativity
1.3
Atomic radius
245 pm
Ionization energy
6.282 eV
Discovery
1950 · Glenn T. Seaborg et al.

Common uses

Neutron sources, cancer treatment, oil well logging

Did you know?

Extremely expensive neutron source worth millions per gram.