SymbolI
Latin nameIodium
Atomic number53
Period5
Element categoryHalogens
Relative atomic mass126.90447
GroupVII.A
Electronegativity
2.5
Oxidation numbers
-1, 1, 3, 5, 7
Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p5
Density [g/cm3]
4.93
State
Solid
Melting point [°C]
113.5
Boiling point [°C]
184.35
Critical point [°C]
546
Critical pressure [MPa]
11.7
Atomic radius [pm]
115
Covalent radius [pm]
133
Thermal conductivity [W m-1K-1]
0.449
Heat capacity [J K-1g-1]
0.145
Discovery
1811
Electrical conductivity [S m-1]
1 · 10-7
1.st ionization energy [eV]
10.4513
2.nd ionization energy [eV]
19.131
3.rd ionization energy [eV]
33.0
Stable isotopes
1
Unstable isotopes
23