Tin, Physical and Chemical Properties

Tin is an ancient metal. It is obtained chiefly from the mineral cassiterite, SnO₂. It is alloyed with copper to form bronze containing 12% Sn, which is used to cast bells, statues, and cannons easily. Pewter, an alloy of 85–90% tin with the remainder of copper, antimony, and lead, was used for cutlery. Tin has long been used as a solder in the form of an alloy with lead, tin accounting for 5–70%. Such solders are used for joining pipes or electric circuits. Tin bonds readily to iron and is used for coating steel to prevent corrosion. Tin-plated steel containers are used for food preservation. Tin is a malleable, ductile silvery-white metal. It is nontoxic but certain organotin compounds are highly toxic.

Tin exists in two modifications: β-tin (the metallic form, or white tin) is stable at room temperature and above room temperature is malleable. In contrast, α-tin (nonmetallic form, or gray tin) is stable below 13.2°C, is brittle with no metallic properties. It is a gray powdery...