Titanium (Ti)

Silvery-gray metal

Titanium is as strong as steel but 45% lighter, and it's completely immune to body fluid corrosion, and with [Ar] 3d² 4s², titanium forms a stable TiO₂ oxide layer that makes it completely biocompatible. Its strength-to-weight ratio is the highest of any structural metal.

Key metrics

Density4.51g/cm³

Melting point1,941K

Boiling point3,560K

Electronegativity1.54Pauling

Discovery

1791discovered

Discovered by: William Gregor
Reactivity profile: Corrosion resistant
Reactivity: Medium
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Ar]}\; \textcolor{#22c55e}{3_{d}^{2}}\; \textcolor{#ef4444}{4_{s}^{2}}

[Ar] 3d2 4s2

Wave function

\Psi_{\text{Ti}} \approx \frac{1}{\sqrt{22!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{22}(\mathbf{r}_{22}) \right|

Probability density $|\Psi|^2$ across the Ti valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 147 pm
Ionization energy: 659 kJ/mol
Electron affinity: 7 kJ/mol
Crystal structure: Hexagonal close-packed (hcp)

Oxidation states

+2+3+4

Acid/base

Neutral

Strongly acidicStrongly basic

State at 25 °CSolid

1941 K3560 K298 K

Emission spectrum

3 transitions

380450500550600650700780

VioletBlueGreenYellowRed

430.6nmTi I (blue)Violet100%

499.1nmTi I (green)Cyan70%

501.4nmTi ICyan60%

Dominant line 430.6 nmRange 431–501 nmTransitions 3