Tin is the fourth element in Group 14 of the periodic table. Its atomic number is 50, its atomic mass is 118.69, and its chemical symbol is Sn.

Properties

Two allotropic forms of tin exist, the - and -forms. The -form of tin is also known as white tin and has a melting point of 450°F (232°C), a boiling point of 4,100°F (2,260°C), and a density of 7.31 grams per cubic centimeter. One of white tin's most interesting properties is its tendency to give off a strange screeching sound when it is bent. This sound is known as "tin cry."

The -form is also known as gray tin and is formed when the -form is cooled to temperatures of less than about 55°F (13°C). Gray tin is a gray amorphous powder. The change from white to gray tin explains an interesting phenomenon that has been observed...