3D Bohr-model representation of the Sodium atom (symbol Na, atomic number Z=11). Electron shell configuration: 2, 8, 1 electrons.
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Bohr model · educational
Bohr model of sodium
Sodium (Na) has 11 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) | 1 |
The Bohr model is a teaching picture: electrons do not travel in circular orbits, but the number of electrons per shell is exact.
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9 minElectron configuration
Full1s² 2s² 2p⁶ 3s¹
Short[Ne] 3s¹
Valence electrons1
KLMNOPQ shells
K2
L8
M1
Electronegativity
Pauling0.93
Allen0.869
Mulliken (eV)—
Atomic radii
Empirical180 pm
Calculated190 pm
Covalent166 pm
Van der Waals227 pm
Ionic radii (Shannon-Prewitt)
+1102 pm
Successive ionisation energies
I₁495.8 kJ/mol
I₂4562 kJ/mol
I₃6910.3 kJ/mol
I₄9543 kJ/mol
I₅13354 kJ/mol
Electron affinity52.8 kJ/mol
Oxidation states
-1+1
Bold states = most common.
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Sodium — 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