Thallium

Post-transition metal

Symbol: Tl

Atomic Number: 81

Standard State: Solid

Atomic Mass: 204.383

Electron Configuration: [Xe]6s2 4f14 5d10 6p1

Electronegativity: 1.62

Atomic Radius: 196

Ionization Energy: 6.108

Melting Point: 577

Boiling Point: 1746

Density: 11.8

Year Discovered: 1861