55 Cs 132.91

Caesium

Category: Alkali metal | State: Solid

Atomic Properties

Atomic Number 55
Atomic Mass 132.91
Electronic Configuration [Xe] 6s¹

Periodic Table Placement

Group 1
Period 6
Block s-block

Physical Properties & Discovery

Melting Point 28.5°C
Boiling Point 671°C
Density 1.873 g/cm³
Discovered By Robert Bunsen & Gustav Kirchhoff (1860)

Frequently Asked Questions about Caesium