Beryllium is the first member of Group 2 of the periodic table. The members of this group are also called the alkaline earth elements. Beryllium's atomic number is 4, its atomic mass is 9.012182, and its chemical symbol is Be.

Properties

Beryllium is a hard, brittle metal with a grayishwhite surface. It is the least dense metal that can be used in construction. It has a melting point of 2,336°F (1,280°C) and a boiling point estimated to be about 4,500°F (2,500°C). Its density is 1.8 grams per cubic centimeter, and it has a high heat capacity and heat conductivity.

One of its important physical properties is transparency to x rays. This property is utilized in the production of beryllium windows for x-ray machines.

Chemically, beryllium is moderately active. It reacts with acids and water to form hydrogen gas and with oxygen to form beryllium oxide (BeO). The beryllium...