Comparison of Bromine and Astatine

Attribute	Bromine ×	Astatine ×
Atomic mass (u)	79.9	209.98715
Standard state	Liquid	Solid
Oxidation states	-1 +1 +5	-1 1 3 5 7
Electron configuration	[Ar]4s²3d¹⁰4p⁵	[Xe]6s²4f¹⁴5d¹⁰6p⁵
Atomic radius (van der waals) (pm)	183	202
Electronegativity (pauling scale)	2.96	2.2
Electron affinity (eV)	3.365	2.8
Ionization energy (eV)	11.814	9.5
Boiling point (K)	331.95	-
Melting point (K)	265.95	575
^1↑Density (g/cm³)	3.11	7
Atomic number	35	85
Group name	Halogen	Halogen
Symbol	Br	At
Discovered (year)	1826	1940