Astatine

Halogen

Symbol: At

Atomic Number: 85

Standard State: Solid

Atomic Mass: 209.9872

Electron Configuration: [Xe]6s2 4f14 5d10 6p5

Electronegativity: 2.2

Atomic Radius: 202

Ionization Energy: 9.5

Melting Point: 575

Boiling Point:

Density: 7

Year Discovered: 1940