Fermium (Fm)
Fermium
Fermium (Fm) is an actinide in period 7. Its relative atomic mass is [257] and the molar mass of the atom is [257] g/mol.
Atomic number 100
Atomic mass [257] predicted
Molar mass [257] g/mol
Category Actinide Unknown
Properties of fermium
| Atomic number | 100 |
|---|---|
| Symbol | Fm |
| Latin name | Fermium |
| Relative atomic mass | [257] |
| Molar mass | [257] g/mol |
| Group, period, block | —, 7, f |
| Category | Actinide |
| State at 20 °C | Unknown |
| Electron configuration | [Rn] 5f¹² 7s² |
| Electronegativity (Pauling) | 1.3 |
Electron configuration of fermium
Electrons per shell
K2L8M18N32O30P8Q2
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹² 6s² 6p⁶ 7s²
Noble-gas notation
100 protons · 100 electrons[Rn] 5f¹² 7s²
Formula and compounds of fermium
Simple substanceFmfermiumMolar mass of Fm: [257] g/mol
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Frequently asked questions
The relative atomic mass of fermium is [257], so the molar mass of the atom is [257] g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹² 6s² 6p⁶ 7s². Noble-gas notation: [Rn] 5f¹² 7s².