55 Cs 132.905451966

Cesium

ALKALI METAL

Phase: Solid

Discovered: Robert Bunsen

Block: S

Summary

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 °C (82 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium is an alkali metal and has physical and chemical properties similar to those of rubidium and potassium.

Appearance: silvery gold

Source: Wikipedia

Physical Properties

Atomic Mass 132.905451966 u

Density 1.93 g/cm³

Melting Point 301.7 K

Boiling Point 944 K

Molar Heat 32.21 J/(mol·K)

Electron Affinity 45.505 kJ/mol

Ionization Energies

1^st: 375.7 kJ/mol

2^nd: 2234.3 kJ/mol

3^rd: 3400 kJ/mol