Alkaline Earth Metals
Strontium (Sr) is atomic number 38, has an atomic weight of 87.62 amu, and has melting and boiling points of 1,430.6°F (777°C) and 2,519.6°F (1,382°C), respectively. A. Crawford identified it as an element in 1790, and in 1808, Davy produced it as the free metal. It occurs in the earth's crust at about 370 parts per million, mostly as the minerals celestite (the sulfate) and strontianite (the carbonate), and occurs in the ocean at about eight parts per million. In addition to its use in fireworks, strontium is a glass additive.