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. Examples in which white pigment, consisting of titanium oxide, is used, are correction fluid and commonly used white paint to repaint walls. It is also used in toothpaste, white road marking paints and in white fireworks. Substances containing titanium are called titaniferous.
The element occurs in numerous minerals with the main sources being rutile and ilmenite, which are widely distributed over the Earth. There are two allotropic forms and five naturally occurring isotopes of this element; 46Ti through 50Ti with 48Ti being the most abundant (73.8%). One of titanium's most notable characteristics is that it is as strong as steel but is only 60% its density. Titanium's properties are chemically and physically similar to zirconium.