NO. 055Alkali

Cs

Cesium

Cesium is an extremely reactive Alkali used in atomic clocks and specialized electronics.

Crystal Structure

Body-centered cubic (bcc)

Atomic Mass132.91 u

Density1.93 g/cm³

Melting Point302 K

Boiling Point944 K

Atomic Radius298 pm

Electronegativity0.79

Ionization Energy376 kJ/mol

Electron Affinity46 kJ/mol

Bonding TypeMetallic

Oxidation States1

Acid/BaseBasic

ReactivityHigh

Electron Configuration

[Xe] 6s1

Discovered ByRobert Bunsen

Year1860

Known Isotopes

Cs-133