Alphabetical Index
Browse by Elements
Keyword Search

ASTM Electrolytes
Macro Etchants
Micro Etchants
Named Etchants
New Etchants

Al and Al Alloys
Cu and Cu Alloys
Fe and Fe Alloys
Ni and Ni Alloys
Carbide Etchants
Fluoride Etchants
Nitride Etchants
Other Etchants
Oxide Etchants
Phosphide Etchants
Single Crystal Etchants
Thin Film Etchants
Wafer Etchants

Help
Home

Astatine

Symbol: At
Atomic Number: 85
Atomic Weight: 209.9871
Element Classification: Halogen
Discovered By: D.R.Corson, K.R.MacKenzie, E. Segre
Discovery Date: 1940 (United States)
Name Origin: Greek: astatos (unstable).

Density (g/cc): n/a
Melting Point (°K): 575
Boiling Point (°K): 610
Appearance: Unstable, radioactive halogen
Atomic Radius (pm): n/a
Atomic Volume (cc/mol): n/a
Covalent Radius (pm): (145)
Ionic Radius: 62 (+7e)
Specific Heat (@20°C J/g mol): n/a
Fusion Heat (kJ/mol): n/a
Evaporation Heat (kJ/mol): n/a
Thermal Conductivity (@25°C W/m K):
Debye Temperature (°K): n/a
Pauling Negativity Number: 2.2
First Ionizing Energy (kJ/mol): 916.3
Oxidation States: 7, 5, 3, 1, -1
Electronic Configuration: [Xe] 4f14 5d10 6s2 6p5
Lattice Structure: n/a
Lattice Constant (Å): n/a
Lattice C/A Ratio: n/a