(From the Latin beryllus, "beryl") A hard, silver-white, metallic chemical element, one of the alkaline-earth metals, found only in combination with others. It forms strong, hard, lightweight alloys with several metals that are used for springs; electrical contacts; in X-ray lithography; and as structural material for high performance aircraft, missiles, spacecraft (such as in the U.S. space shuttle), and satellites. Beryllium is also used as a moderator or reflector in nuclear reactors. It is found mostly in minerals like beryl and chrysoberyl.
Symbol: Be
Atomic number: 4
Atomic weight: 9.012182
Density (at
room temperature and
pressure): 1.848
g/
cc
Melting point: 1,287°
C
Boiling point: 2,470°
C
Valence: +2
Ground state electron configuration: [
He]2s
2