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:  98898
Density:        87.98 g/cm3
Melting Point:  5434 °C
 Boiling Point: 232 °C