Symbol:  Cs

Atomic Mass: 132.9054519 (2)

Atomic Number: 55

# of protons: 55

# of electrons: 55

#of neutrons: 78

Boiling Point: 944K 671°C 1240°F

Melting Point: 301.7K 28.55°C 83.39°F

Freezing Point:

Density:1.873g/cc @ 300K

Electronegativity: 0.79 (Pauling); 0.86 (Allrod Rochow)

Cesium is the most sublime and electropositive of all true elements. It was discovered spectroscopically, in mineral water from Durkheim Germany by Robert Bunsen (of burner fame) and Gustaff Kirchhoff in 1860

Cesium occurs naturally in the minerals lepidolite and pollucite, the latter a hydrated aluminum cesium silicate.

Cesium exists in the form of a solid

Cesium is an alkali metal, in the same group as lithium, sodium, potassium, and rubidium, and is similarly reactive, but to a much higher degree due to its extreme electropositivity