12Mg24.305
Magnesium
Alkaline earth metalsBlock sPeriod 3Group 2solid at 20 °C
- Configuration :
- [Ne] 3s²
- Atomic mass :
- 24.305 u
- French :
- Magnésium
3D Bohr-model representation of the Magnesium atom (symbol Mg, atomic number Z=12). Electron shell configuration: 2, 8, 2 electrons.
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Bohr model · educational
Bohr model of magnesium
Magnesium (Mg) has 12 electrons, spread over 3 shells. The diagram places them on circles around the nucleus, from the K shell — the closest — outward.
| Shell | Electrons |
|---|---|
| K (n = 1) | 2 |
| L (n = 2) | 8 |
| M (n = 3) | 2 |
The Bohr model is a teaching picture: electrons do not travel in circular orbits, but the number of electrons per shell is exact.
Related lesson
Ionic bonding
Electron transfer from metal to non-metal. Ionic crystal lattice, lattice energy (qualitative).
10 minElectron configuration
Full1s² 2s² 2p⁶ 3s²
Short[Ne] 3s²
Valence electrons2
KLMNOPQ shells
K2
L8
M2
Electronegativity
Pauling1.31
Allen1.293
Mulliken (eV)—
Atomic radii
Empirical150 pm
Calculated145 pm
Covalent141 pm
Van der Waals173 pm
Ionic radii (Shannon-Prewitt)
+272 pm
Successive ionisation energies
I₁737.7 kJ/mol
I₂1450.7 kJ/mol
I₃7732.7 kJ/mol
I₄10542.5 kJ/mol
I₅13630 kJ/mol
Electron affinity—
Oxidation states
+1+2
Bold states = most common.
Warm-up
Magnesium — do you remember?
3 questions on this page. The right answer shows every time, and nothing is asked of you to play.
No account · one minute