55Cs
Cesium
Alkali MetalCesium (Cs) is element 55, an alkali metal, in period 6 and group 1 of the periodic table. Its standard atomic weight is 132.905, it melts at 28.44 °C and boils at 671 °C. Discovered by Robert Bunsen, 1860.
Atomic Number55
SymbolCs
NameCesium
Atomic Weight132.905 u
CategoryAlkali Metal
Period6
Group1
Melting Point28.44 °C
Boiling Point671 °C
Density1.873 g/cm³
Electron Config[Xe] 6s1
Discovered ByRobert Bunsen, 1860