Tin is a chief group metal in group 14 of the periodic table. Tin is a chemical element with the symbol Sn and atomic number 50. It displays chemical likeness to neighbouring group 14 elements, germanium and lead. Tin is found mainly from the mineral cassiterite, where it exists as tin dioxide, SnO2. This silvery, pliable poor metal is not simply oxidized in air and is used to coat other metals to prevent corrosion.