Periodic Table
100
Fm
257
Fermium
ActinoidHeaviest element formed by neutron bombardment.
Electronic Configuration
[Rn] 5f¹² 7s²or1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 5f¹² 7s²
Electron shells
2e⁻n=1
8e⁻n=2
18e⁻n=3
32e⁻n=4
30e⁻n=5
8e⁻n=6
2e⁻n=7
Properties
Atomic number
100
Atomic mass
257 u
Category
Actinoid
Block / Group / Period
f · — · 7
Valence electrons
2
Oxidation states
+3
Electronegativity
1.3
Atomic radius
186 pm
Ionization energy
627 kJ/mol
Electron affinity
34 kJ/mol
Melting point
1800 K / 1527 °C
Boiling point
— / —
Density
9.7 g/cm³
State at 25 °C
solid
Personal Notes
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