NO. 100Actinide

Fm

Fermium

Fermium is a synthetic radioactive element with no practical applications outside research. It is produced in minute quantities in nuclear reactions.

Crystal Structure

Hexagonal close-packed (predicted)

Atomic Mass257 u

Density9.7 g/cm³

Melting Point1527 K

Boiling Point1125 K

Atomic Radius187 pm

Electronegativity1.3

Ionization Energy627 kJ/mol

Electron Affinity0 kJ/mol

Bonding TypeMetallic

Oxidation States2, 3

Acid/BaseBasic

ReactivityHigh

Electron Configuration

[Rn] 5f12 7s2

Discovered ByLawrence Berkeley Lab

Year1952

Known Isotopes

Fm-257