3D Bohr-model representation of the Scandium atom (symbol Sc, atomic number Z=21). Electron shell configuration: 2, 8, 9, 2 electrons.
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Bohr model · educational
Bohr model of scandium
Scandium (Sc) has 21 electrons, spread over 4 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) | 9 |
| N (n = 4) | 2 |
The Bohr model is a teaching picture: electrons do not travel in circular orbits, but the number of electrons per shell is exact.
Electron configuration
Full1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s²
Short[Ar] 3d¹ 4s²
Valence electrons3
KLMNOPQ shells
K2
L8
M9
N2
Electronegativity
Pauling1.36
Allen1.19
Mulliken (eV)—
Atomic radii
Empirical160 pm
Calculated184 pm
Covalent170 pm
Van der Waals—
Ionic radii (Shannon-Prewitt)
+374.5 pm
Successive ionisation energies
I₁633.1 kJ/mol
I₂1234.9 kJ/mol
I₃2388.6 kJ/mol
I₄7090.6 kJ/mol
I₅8843 kJ/mol
Electron affinity18.1 kJ/mol
Oxidation states
+1+2+3
Bold states = most common.
Warm-up
Scandium — 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