sN

Tin (Sn, atomic number 50) is a soft, silvery-white metal in group 14 of the periodic table. It occurs in two allotropes: white tin, which is stable at room temperature, and gray tin, which forms below about 13.2°C and is brittle, a transition that can cause tin pest in older samples. Tin's melting point is 231.93°C, and its boiling point is about 2,625°C. The surface rapidly forms a thin oxide layer that protects the metal from further corrosion.

Most tin is obtained from the ore cassiterite (tin oxide, SnO2). After mining, the ore is processed by gravity separation and smelting, followed by refining to produce metallic tin. Major producers include China and Indonesia, with significant output from Peru and Russia; tin is often mined as a byproduct of alluvial deposits and hard rock mining.

Tin has a long history of use. The symbol Sn derives from the Latin stannum. In antiquity tin was alloyed with copper to make bronze, a key step in the Bronze Age. In modern times tin is widely used in coatings, known as tinplate, and in solders for electronics. Tin can form stable alloys, notably bronze (copper-tin) and pewter (tin with copper, antimony, or lead).

Applications and isotopes: The dominant contemporary use of tin is in solder for electronics and electrical components, especially lead-free solders. Tin coatings protect steel cans for food storage. Tin is also used in various alloys, catalysts, and glass production. Tin has ten stable isotopes—the most of any element—and several radioisotopes are used in scientific research.