In elemental form, boron atoms are bonded into units containing 12 atoms. The resulting shape, called an icosahedron, and has 20 faces. The name is derived from the Greek words for "twenty-faced."

Physical Properties

Atomic Number: 5
Atomic Weight: 10.81
Electron Configuration: 1s²2s²2p¹
First Ionization Energy: 899 kJ/mol
Second Ionization Energy: 2422 kJ/mol
Melting Point: 2300^oC
Third Ionization Energy: 3657 kJ/mol