Full configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s²
In the short form, [Ar] stands for the 18 electrons of argon, the noble gas before titanium. Only the electrons after it are written out.
Orbital diagram
Outer subshells only. Each box is an orbital; electrons fill singly first (Hund's rule), then pair up with opposite spins.
What the configuration tells you
Titanium is in group 4, period 4, in the d-block. It has 2 unpaired electrons in the ground state, so the atom is paramagnetic.
Configuration of titanium ions
| Ion | Configuration | Unpaired | Moment (BM) |
|---|---|---|---|
| Ti²⁺ | [Ar] 3d² | 2 | 2.83 |
| Ti³⁺ | [Ar] 3d¹ | 1 | 1.73 |
| Ti⁴⁺ | [Ar] | 0 | 0.00 |
Moment is the spin-only magnetic moment μ = √(n(n + 2)) Bohr magnetons, where n is the number of unpaired electrons. Positive ions lose electrons from the outermost shell first, so transition metals lose their 4s or 5s electrons before d.
Nearby elements
| Z | Element | Configuration |
|---|---|---|
| 19 | Potassium | [Ar] 4s¹ |
| 20 | Calcium | [Ar] 4s² |
| 21 | Scandium | [Ar] 3d¹ 4s² |
| 23 | Vanadium | [Ar] 3d³ 4s² |
| 24 | Chromium | [Ar] 3d⁵ 4s¹ |
| 25 | Manganese | [Ar] 3d⁵ 4s² |
Questions students ask
What is the electronic configuration of titanium?
[Ar] 3d² 4s², or in full, 1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s². Titanium has atomic number 22.
How many electrons are in each shell of titanium?
2, 8, 10, 2 (K, L, M, N… shells in order).
How many unpaired electrons does titanium have?
2 in the ground state, so titanium atoms are paramagnetic.
What is the electronic configuration of Ti²⁺?
[Ar] 3d², with 2 unpaired electrons.