Titanium (Ti)
“As strong as steel at barely half the weight — and so polite to human flesh that bone cells grow onto it as if it were their own.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
Characteristics
- Configuration [Ar] 3d² 4s² — Period 4, Group 4, d-block; in compounds it prefers the +4 oxidation state, as in the snow-white TiO₂ that colours half the world.
- The best strength-to-weight bargain among structural metals: as strong as many steels at little more than half steel’s density — hence jet engines, hence racing bikes.
- Corrosion-proof behind a passive TiO₂ film only nanometres thick: seawater, wet chlorine and even room-temperature aqua regia cannot get through.
- The body’s honoured guest — untouched by body fluids and non-toxic, it lets bone cells grip its surface directly, a bond surgeons call osseointegration.
A lustrous, dark silvery-grey metal, light for all its strength. A polished face gleams like steel, but the gleam survives seawater, sweat and even aqua regia, because within a blink of exposure the surface seals itself beneath an invisible skin of titanium dioxide.
Where you meet it
✦ Uses
- Artificial joints and dental implants — replacement hips, knees and tooth roots of titanium sit inside patients for decades without rusting or rejection.
- Aeroplanes — from jet-engine blades to landing gear, airframes gulp titanium wherever heat and salt would rot lesser metals; a Boeing 787 is roughly a seventh titanium by weight.
- Racing bicycles — a titanium frame famously outlasts its rider, pairing steel’s springy ride with aluminium’s lightness.
- Titanium dioxide — the whitest white pigment on Earth, painting walls, whitening toothpaste and paper, and blocking UV in the sunscreen on Bangladeshi skins.
◍ Everyday examples
- The tube of toothpaste in your bathroom and the white paint on your walls both owe their brightness to titanium dioxide powder.
- The heavy dark grains mixed through the beach sands of Cox’s Bazar include ilmenite, an iron-titanium oxide — the very ore the world refines for titanium metal.
- A grandfather’s new hip joint walking him to the mosque, or a cousin’s gleaming racing bicycle — both are titanium quietly at work.
History & name
In 1791 the Cornish clergyman and part-time mineralogist William Gregor analysed the strange black sand of the Menaccan valley and isolated a white oxide he could not match to any known element. Four years later in Berlin, Martin Heinrich Klaproth found the same stranger inside the mineral rutile, judged it a new element and named it titanium — after the Titans, the mighty giant sons of Earth in Greek myth — admitting that no ancient name could do justice to a metal of such hidden strength. Neither man ever saw it pure: the metal surrendered only in 1910 to Matthew Hunter’s sodium, and in 1925 the iodide process finally delivered 99.9% titanium.