4Be
Beryllium
베릴륨 · ベリリウム
Alkaline earth
Atomic number4
ElementBe — Beryllium
Atomic mass9.0122
CategoryAlkaline earth
Group2
Period2
Electron config[He] 2s2
Shells2,2
State (RT)Solid
Melting pt1287°C
Boiling pt2469°C
Electronegativity1.57
Discovered1798
Main usesAerospace alloys, X-ray windows
2 · 2