Titanium
Atomic Data
| Atomic Number | 22 |
| Symbol | Ti |
| Atomic Weight | 47.867 u |
| Density (STP) | 4.506 g/cm³ |
| Melting Point | 1667.85 °C (1941 K) |
| Boiling Point | 3286.85 °C (3560 K) |
| Electronegativity | 1.54 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d2 4s2 |
| Oxidation States | +2, +3, +4 |
| Phase at STP | Solid |
| Category | Transition metal |
| Period / Group | 4 / 4 |
| CAS Number | 7440-32-6 |
Electron Configuration
[Ar] 3d2 4s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 2 | 20 |
| N | 4 | 4s | 2 | 22 |
| Total | 22 | 22 | ||
Isotopes of Titanium
Titanium has five stable naturally occurring isotopes. ⁴⁸Ti dominates at 73.72% abundance; the remaining four isotopes each account for less than 9% of natural titanium.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Titanium-46 | ⁴⁶Ti | 22 | 24 | 8.25% | Stable |
| Titanium-47 | ⁴⁷Ti | 22 | 25 | 7.44% | Stable |
| Titanium-48 | ⁴⁸Ti | 22 | 26 | 73.72% | Stable |
| Titanium-49 | ⁴⁹Ti | 22 | 27 | 5.41% | Stable |
| Titanium-50 | ⁵₀Ti | 22 | 28 | 5.18% | Stable |
Abundance & Occurrence
Titanium is the ninth most abundant element in Earth’s crust, found primarily in the minerals ilmenite (FeTiO₃) and rutile (TiO₂). Major deposits occur in Australia, South Africa, Canada, and India; ilmenite is by far the dominant ore mined globally for titanium production.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Safety & Handling
- Dust and powder fire hazard: Titanium metal in bulk is not reactive under normal conditions, but fine titanium powder and swarf are flammable and can ignite spontaneously. Machining or grinding produces fine particles that require dry-sand or Class D fire extinguishers — never water or CO₂, which can intensify a titanium fire.
- Biocompatibility: Solid titanium is non-toxic and one of the most biocompatible structural metals known. It is not absorbed by the body, does not corrode in physiological fluids, and provokes minimal immune response, making it safe for permanent implants.
- Titanium tetrachloride (TiCl₄) hazard: The main precursor chemical used in refining reacts violently with moisture, releasing corrosive hydrogen chloride (HCl) fumes. Handling requires full protective equipment and dry, inert-atmosphere conditions.
- Titanium dioxide (TiO₂): Classified as a possible human carcinogen (IARC Group 2B) when inhaled as fine dust or nanoparticles over prolonged periods; standard dust-control measures and respiratory protection apply in industrial settings.
- General handling: Bulk titanium components and alloys present minimal health risk. Good ventilation and standard metalworking practices are sufficient; keep powders away from ignition sources and oxidising agents.
Titanium in the Real World
Real-World Uses
- Aerospace structural components — Titanium alloys are used extensively in airframe structures, jet engine fan blades, compressor discs, and spacecraft because they combine near-steel strength with roughly half the weight, and resist the corrosion and fatigue that occur at altitude.
- Biomedical implants — Hip and knee joint replacements, dental implants, bone screws, and spinal rods are routinely made from titanium alloys (especially Ti-6Al-4V) because the metal integrates directly with bone tissue and remains inert for decades in the body.
- White pigment (TiO₂) — Titanium dioxide is the world’s most widely used white pigment, providing brightness and opacity in paints, coatings, plastics, paper, inks, and cosmetics; it also serves as the UV-blocking agent in physical sunscreens.
- Desalination plants — Titanium heat exchangers and pipe systems resist the highly corrosive saltwater environment inside desalination facilities, lasting far longer than stainless steel alternatives at a competitive lifecycle cost.
- Sporting goods — High-performance bicycle frames, golf club heads, tennis racket frames, and climbing gear use titanium alloys to achieve the stiffness and strength of steel at a fraction of the weight.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
Why is titanium used in aerospace?
Titanium has one of the highest strength-to-weight ratios of any metal, roughly equivalent in strength to steel at about 45% of the weight. It also withstands the temperature extremes and corrosive environments encountered in jet engines and airframes, making it indispensable for aircraft structures, turbine blades, and spacecraft components.
Is titanium safe in the human body?
Titanium is highly biocompatible — it is non-toxic, non-allergenic, and integrates with living bone tissue through a process called osseointegration. These properties make it the material of choice for dental implants, joint replacements, bone screws, and surgical instruments.
What is titanium dioxide used for?
Titanium dioxide (TiO₂) is the world’s most widely used white pigment, giving brightness and opacity to paints, coatings, plastics, paper, and cosmetics. It is also used in sunscreens as a UV-blocking agent, and in food products as a whitening additive (E171).
Who discovered titanium?
William Gregor, a Cornish clergyman and amateur mineralogist, first identified titanium in 1791 from an iron-bearing black sand (ilmenite) found in Manaccan, Cornwall. He called the new oxide ‘manaccanite’. The element was independently rediscovered in 1795 by Martin Heinrich Klaproth, who named it titanium after the Titans of Greek mythology.