Caesium or cesium is a chemical element with symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28.5C, which makes it one of only five elemental metals that are liquid at or near room temperature.

Atomic Weight: 933.21
Density        124.2
Melting Point: 43.1
Boiling Point: 23.6