NO. 103Actinide

Lr

Lawrencium

Lawrencium is the final actinide element and exhibits unusual electron configuration behavior, blurring the line between actinides and Transitions.

Crystal Structure

Hexagonal close-packed (predicted)

Atomic Mass266 u

Density14.4 g/cm³

Melting Point1900 K

Boiling Point1030 K

Atomic Radius191 pm

Electronegativity1.3

Ionization Energy470 kJ/mol

Electron Affinity0 kJ/mol

Bonding TypeMetallic

Oxidation States3

Acid/BaseBasic

ReactivityHigh

Electron Configuration

[Rn] 5f14 7s2 7p1

Discovered ByLawrence Berkeley Lab

Year1961

Known Isotopes

Lr-266