103 Lr 266

Lawrencium

Actinide

Lawrencium (Lr) is a chemical element with atomic number 103, classified as a actinide. At room temperature it is a solid. It was discovered in 1961 by Albert Ghiorso et al..

Properties

Atomic number
103
Atomic mass
266 u
Category
Actinide
Group
3
Period
7
Block
d-block
Electron configuration
[Rn] 5f¹⁴ 6d¹ 7s²
Phase at STP
Solid
Density
Melting point
1900 K (1626.8 °C)
Boiling point
Electronegativity
Atomic radius
Ionization energy
4.96 eV
Discovery
1961 · Albert Ghiorso et al.

Common uses

Research only

Did you know?

Last of the actinides and named after Ernest Lawrence.