Fm

Fermium

Element 100 · 257.09511 u

Actinide f-block Period 7 Solid at RT Radioactive t½ 100.5 days Synthetic Wikipedia →

Fermium is the heaviest element that can be produced by neutron capture.

Physical Properties

Atomic Mass257.09511 u
Density9.7 g/cm³
Melting Point1800.0 K
AppearanceSilvery metallic (predicted)
State at Room TempSolid

Chemical Properties

Electronegativity1.3 (Pauling)
1st Ionization Energy627.0 kJ/mol
Electron Affinity33.96 kJ/mol
Oxidation States+2, +3

Atomic Properties

Electron Configuration[Rn] 5f12 7s2

Discovery

Discovered ByAlbert Ghiorso and others
Discovery Year1952
LocationBerkeley, California, USA
Named AfterNamed after Enrico Fermi, pioneer of nuclear reactors

About Fermium

Fermium was co-discovered with einsteinium in hydrogen bomb debris. It is the heaviest element producible by neutron bombardment. Only tiny amounts have been made.

Uses & Applications

No practical applications. Scientific research only.

Fun Fact

Fermium is the heaviest element producible by neutron bombardment. Anything heavier requires smashing nuclei together in accelerators.

Isotopes

Mass Number Abundance Half-Life Stable
255 - 20.07 hours No
257 - 100.5 days No

Electron Configuration

[Rn] 5f12 7s2

Compare

Compare Fermium with other elements

Open Comparison Tool
← Einsteinium Back to Table Mendelevium →