Sodium is a soft, silvery-white metal that is the 11th element on the periodic table with an atomic number of 11. It was discovered in 1807 by Sir Humphrey Davy through the electrolysis of caustic soda. Sodium has a boiling point of 883 degrees Celsius and melting point of 97.8 degrees Celsius. It is very reactive, especially with water, and causes severe burns, eye damage, and is harmful if ingested or in contact with skin. Common minerals and compounds containing sodium include table salt, soda niter, cryolite, zeolite, and sodium chloride.