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Element 85 - Astatine (At) sound

From astatos, or unstable; discovered 1940. Astatine, prepared by bombarding bismuth atoms with helium nuclei, is radioactive and has a maximum half life of 8.1 hours. Its detection is recorded in the notebook of one of its discoveres, American physicist D.R. Corson.

Properties

Atomic Number: 85
Atomic Weight: (210)
Electron Configuration (at ground state): 1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p5
Oxidation States (Bold most stable): -1, +1, +3, +5, +7
Boiling Point (K): 610
Melting Point (K): 575
Number of natural radioactive isotopes: 3
Mass Number (Bold naturally occurring) -- Half-Life -- Disintigration Type: 209 -- 5.4 hours -- orbital electron capture, alpha particle emission
210 -- 8.1 hours -- orbital electron capture
211 -- 7.21 hours -- orbital electron capture, alpha particle emission
Covalent Radius (Å): 1.47
Atomic Radius (Å): 1.45
Electronegativity (Pauling's): 2.2
Heat of Vaporization (kJ/mol): 30
Heat of Fusion (kJ/mol): 12
Thermal Conductivity (at 300K -- W m-1 K-1): 1.7