On the periodic table, beryllium is the lightest alkaline earth metal.
Beryllium has atomic number 4 and the symbol Be. It occupies the top position in group 2, whose elements are called the alkaline earth metals. Beryllium is a lightweight, stiff, gray metal with a relatively high melting point for its low mass.
Its low density and rigidity make beryllium useful in specialized aerospace, defense, optical, and scientific applications. Beryllium copper alloys combine copper’s conductivity with greater strength. However, beryllium dust and fumes can be hazardous, so handling it requires strict industrial controls.
Beryllium is often confused with boron because both are light elements near the top of the table. Boron is a metalloid in group 13, whereas beryllium is a group-2 metal.