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53I126.904
Iodine
Diatomic NonmetalIodine is a chemical element with symbol I and atomic number 53. The name is from Greek ἰοειδής ioeidēs, meaning violet or purple, due to the color of iodine vapor. Iodine and its compounds are primarily used in nutrition, and industrially in the production of acetic acid and certain polymers.
Phase: SolidAppearance: lustrous metallic gray, violet as a gas
2, 8, 18, 18, 7
Physical Properties
Atomic Mass126.904473 u
Density4.933 g/cm³
Melting Point386.85 K
Boiling Point457.4 K
Period5
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p5
Semantic Config[Kr] 4d10 5s2 5p5
Shells2, 8, 18, 18, 7
Electron Affinity295.1531 kJ/mol
Electronegativity2.66
Ionization Energies
IE1: 1008.4 kJ/molIE2: 1845.9 kJ/molIE3: 3180 kJ/mol
Discovery
Discovered byBernard Courtois