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Atomic Number	85

Atomic Symbol	At

Atomic Weight	[210 amu]

Group	Halogen, 17

Form	Solid

Melting Point	302 °C (575.6 °F, 575.15 °K)

Heat of Fusion	6 kJ/mol (approx.)

Heat of Vaporization	40 kJ/mol (approx.)

Electronegativity (on Pauling scale	2.2

Ground State Electron Configuration	5d¹⁰ 6s² 6p⁵

Oxidation State(s)	+1, +3, +5, +7, -1

Selected Radioisotopes	²¹⁰At, ²¹¹At

Atomic Radius	127 pm

Discovered by	Corson; MacKenzie; Segre, 1940