Fermium (Fm)

From Wikipedia, the free encyclopediaFermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.

Fermium in the periodic table

SymbolFm
Atomic number100
Group0
Period7
Blockf
Element categoryActinide

Physical properties

Phase at STPSolid
Density g/cm3
Atomic weight257 u
Melting point1800 K
1526.85 °C
2780.33 °F
Boiling point K
°C
°F

Atomära egenskaper

Electronegativity (Pauling Scale)1.3
Electron affinity33.96 kJ/mol
Ionization energies
1627 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f12 6s2 6p6 7s2
Electrons per shell2, 8, 18, 32, 30, 8, 2

History

Discovered1952
Discovered byLawrence Berkeley National Laboratory