Cesium

Alkali metal

Symbol: Cs

Atomic Number: 55

Standard State: Solid

Atomic Mass: 132.9055

Electron Configuration: [Xe]6s1

Electronegativity: 0.79

Atomic Radius: 343

Ionization Energy: 3.894

Melting Point: 301.59

Boiling Point: 944

Density: 1.93

Year Discovered: 1860