Periodic Table of Elements

53

Iodine

126.90

Iodine was discovered by the French chemist Barnard Courtois(1777-1838) in 1811.

Name: Iodine
Symbol: I
Atomic number: 53
Atomic weight: 126.90
State: solid
Group, period, block: 17, 5, p
Color: lustrous metallic gray, violet as a gas
Classification: halogen
Electron configuration: 4d10 5s2 5p5
2,8,18,18,7

Physical properties

Density: 4.933 g/cm-3
Melting point: 386.85 K, 113.7 C, 236.66 F
Boiling point: 457.4 K, 184.3 C, 363.7 F

Atomic properties

Oxidation states: 7, 5, 3, 1, -1
Electronegativity: 2.66 (Pauling scale)
Ionization energies: 1st: 1008.4 kJmol-1
Covalent radius: 1393 pm
Van der Waals radius: 198 pm
  • I
  • Electron Configuration

Isotopes

There is one naturally occurring isotope of iodine exists, 127I.