55Cs
Caesium
세슘 · セシウム
Alkali metal
Atomic number55
ElementCs — Caesium
Atomic mass132.91
CategoryAlkali metal
Group1
Period6
Electron config[Xe] 6s1
Shells2,8,18,18,8,1
State (RT)Solid
Melting pt28°C
Boiling pt671°C
Electronegativity0.79
Discovered1860
Main usesAtomic clocks, drilling fluids
2 · 8 · 18 · 18 · 8 · 1