Titanium is a chemical element in the periodic table that has the symbol Ti and atomic number 22. It is a light, strong, lustrous, corrosion-resistant (including resistance to sea water and chlorine) transition metal with a white-silvery-metallic colour. Titanium is used in strong light-weight alloys (most notably with iron and aluminium) and its most common compound, titanium dioxide, is used in white pigments.
Titanium is well known for its excellent resistance to corrosion; it is almost as resistant as platinum, being able to withstand attack by acids, moist chlorine gas, and by common salt solutions. Pure titanium is not soluble in water but is soluble in concentrated acids. A metallic element, it is also well-known for its high strength-to-weight ratio.
Due to excellent resistance to sea water, it is used to make propeller shafts and rigging and in the heat exchangers of desalination plants and in heater-chillers for salt water aquariums, and lately diver knives as well.
It is used to produce relatively soft artificial gemstones.
Titanium has occasionally been used in construction: the 150-foot (45 m) memorial to Yuri Gagarin, the first man to travel in space, in Moscow, is made of titanium for the metal's attractive colour and association with rocketry. The Guggenheim Museum Bilbao and the Cerritos Library were the first buildings in Europe and North America, respectively, to be sheathed in titanium panels.
