Atomic number 22
Ti
Titanium
- Ti
- Ti
- + phase
- − phase
Drag to rotate; pinch or Ctrl + scroll to zoom. Arrow keys rotate, + − zoom, R resets.
Shells are a teaching model: an electron does not travel on a ring at a fixed distance.
- Category
- Transition metal
- Period
- 4
- Group
- 4
- Block
- d
- Standard atomic weight
- 47.867(1) Da
- Electron configuration
- [Ar] 3d2 4s2
- Phase at 25 °C
- solid
- Melting point
- 1668 °C
- Boiling point
- 3287 °C
- Density
- 4.5 g/cm3
- Electronegativity (Pauling)
- 1.54
- Discovered
- 1791, William Gregor
Neighbours in the table
Martin Heinrich Klaproth named titanium in 1795 after the Titans of Greek myth, the Earth’s first sons. CIAAW’s history on PubChem’s record gives his reason: it had shown no characteristic property to name it by. William Gregor had found it in 1791, in ilmenite from the Menachan parish, and called the mineral menachanite and its element menachin.
Titanium adds two 3d electrons and a 4s pair to argon’s core, [Ar] 3d2 4s2, its shells running 2, 8, 10 and 2. The 4s pair went in first. OpenStax has the 3d orbital less penetrating, less of it near the nucleus, and more shielded, inner electrons offsetting the nucleus’s pull, hence higher in energy. Ionisation takes the s electrons before the d, and losing all four gives titanium(IV). OpenStax calls the highest state the most stable for scandium, titanium and vanadium. TiCl2 and TiCl3 melt high, as ionic compounds do; TiCl4 is a volatile liquid held by covalent bonds.
Los Alamos describes the pure metal as lustrous, white and dimorphic: a hexagonal alpha form changes very slowly to a cubic beta form at about 880 °C. Oxygen combines with it at red heat, chlorine at 550 °C, and Jefferson Lab counts it among the few elements that burn in pure nitrogen. It is ductile only when free of oxygen.
Where it is found
PubChem’s element record puts titanium at 5.65 × 103 milligrams per kilogram of crust, about 0.57 per cent. Jefferson Lab and Los Alamos both rank it ninth among the crust’s elements. Igneous rocks, and the sediments derived from them, nearly always hold some. Its main minerals are rutile, TiO2; ilmenite, FeTiO3, the one Gregor worked on; and sphene, CaTiSiO5. Seawater holds a thousandth of a milligram per litre.
Off the Earth it is in meteorites and in the sun. Rocks brought back by Apollo 17 held 12.1 per cent TiO2, a higher share than earlier Apollo missions had returned. In M-type stars, Los Alamos adds, bands from titanium oxide stand out in the spectrum.
Ilmenite supplies about 90 per cent of the titanium minerals the world consumes. Mines yielded an estimated 9.4 million metric tons of contained TiO2 in 2024, China digging about a third of the ilmenite, Mozambique and South Africa next. The United States has one mining company, near Nahunta in Georgia and Starke in Florida, and imported 86 per cent of what it used. More than 95 per cent of that went to pigment plants.
Why it matters
CIAAW credits the first isolation of the metal to the Swedish chemists Nilson and Pettersson; Los Alamos calls their 1887 metal impure. Pure metal waited until 1910, when Matthew Hunter heated the tetrachloride with sodium inside a steel bomb, a sealed pressure vessel. Titanium stayed a laboratory curiosity until 1946, when Kroll showed it could be made commercially by reducing the tetrachloride with magnesium, a route still largely in use.
The US Geological Survey reports that most of the metal went to aerospace in 2024, the rest to armour, marine hardware, chemical processing, medical implants, power generation and other uses. Los Alamos names aircraft and missiles as the principal use of its alloys, where light weight, strength and a tolerance of temperature extremes count together. Bicycle frames sometimes use it, and jewellery often does.
The largest use of the element, on Los Alamos’s page, is not the metal but the oxide. Titanium dioxide pigment goes into house paint and artists’ paint because it is permanent and covers well; the US Geological Survey valued 2024 US pigment output at about $3 billion. Titanium paint reflects infrared well, and solar observatories, where heat spoils the viewing, use much of it. Pure TiO2 is relatively clear, and the star in a star sapphire or ruby comes from TiO2 within the stone.
Properties
| Property | Value | Unit | Source |
|---|---|---|---|
| Atomic number | 22 | ||
| Standard atomic weight | 47.867(1) Da | Da | IUPAC/CIAAW 2024 |
| Melting point | 1668 °C | °C | Los Alamos: 1668 °C |
| Boiling point | 3287 °C | °C | Los Alamos: 3287 °C |
| Density | 4.5 g/cm3 | g/cm3 | |
| Electronegativity (Pauling) | 1.54 | ||
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d2 | ||
| Phase at 25 °C | solid |
Safety
A titanium ring, bicycle frame or hip implant poses no hazard, and Los Alamos calls the metal physiologically inert. On PubChem’s record 606 of 808 company reports, 75.0%, find no GHS hazard criterion met. The one caution the safety summary lists concerns the powder, a flammable solid that can heat by itself and catch fire in air. The PubChem Laboratory Chemical Safety Summary is the sheet for that form.
Questions
Why is titanium so strong and light?
Los Alamos gives the comparison: titanium is as strong as steel at 45 per cent less weight, and 60 per cent heavier than aluminium but twice as strong. A cubic centimetre weighs 4.5 grams. The US Geological Survey finds few materials matching its ratio of strength to weight and its corrosion resistance; in high-strength work it competes with aluminium, composites, intermetallics, steel and superalloys. Alloyed, it goes principally into aircraft and missiles.
Does titanium rust?
Its corrosion resistance is excellent, on Los Alamos's page, and salt water leaves it sound enough for the propeller shafts and rigging of ships. It resists dilute sulfuric and hydrochloric acids, most organic acids, chloride solutions and most chlorine gas, on the same page. The metal does take up oxygen, but at red heat, and OpenStax lists TiO2 among the oxides made by heating a first-series metal in air. Los Alamos also sees potential for it in desalination plants.
Why is titanium used for hip replacements?
It does not react inside the human body, in Jefferson Lab's words on PubChem's record, and that is the reason the record gives for its use in artificial hips, pins for broken bones and other implants. Los Alamos calls the metal physiologically inert, and Haz-Map, in PubChem's safety summary, knows of no role for it as a trace mineral in the diet. The metal's high cost, Jefferson Lab adds, has limited how widely it is used.
What is titanium dioxide used for?
Mostly to make things white; Jefferson Lab, on PubChem's record, calls it the pigment for white paint. TiO2 pigment's leading uses are paints, then plastics, then paper, on the US Geological Survey's list, with catalysts, ceramics, coated fabrics, floor coverings, roofing granules and printing ink behind them. US plants made about 850,000 metric tons in 2024; imported pigment landed at about $3,200 a ton. Kaolin, talc and calcium carbonate, ground or precipitated, are its competitors as a white pigment.
Is titanium radioactive?
Natural titanium is not. Los Alamos counts five natural isotopes, masses 46 to 50, all stable, and CIAAW's figures on PubChem's record put titanium-48 at 73.72 per cent of the atoms. Unstable isotopes exist too: the longest-lived in PubChem's AMDC table is titanium-44, with a half-life of 59.1 years, and titanium-45 lasts 184.8 minutes. IUPAC's Periodic Table of the Elements and Isotopes, on PubChem's record, uses the ratio of titanium-50 to titanium-46 to study the Solar System's early history.
Sources
- PubChem, element 22 (titanium)
- Periodic-Table-JSON by Bowserinator (CC BY-SA 3.0)
- IUPAC/CIAAW, Abridged Standard Atomic Weights 2024
- PubChem Laboratory Chemical Safety Summary for titanium (CID 23963)
- Los Alamos National Laboratory, Periodic Table of Elements: Titanium (archived 14 September 2026)
- OpenStax, Chemistry 2e, §6.4 Electronic Structure of Atoms (Electron Configurations)
- OpenStax, Chemistry 2e, §19.1 Occurrence, Preparation, and Properties of Transition Metals and Their Compounds
- US Geological Survey, Mineral Commodity Summaries 2025: Titanium and Titanium Dioxide
- US Geological Survey, Mineral Commodity Summaries 2025: Titanium Mineral Concentrates