Symbol I
Atomic Number 53
Atomic Mass 126.9045 g.mol -1
Discovered by Bernard Courtois in 1811

Chemical Properties of Iodine

Group 17 Melting point 113.7°C, 236.7°F, 386.9 K  
Period 5 Boiling point 184.4°C, 363.9°F, 457.6 K
Block p Density (g cm−3) 4.933
Atomic number 53 Relative atomic mass 126.904
State at 20°C Solid Key isotopes 127I
Electron configuration [Kr] 4d10 5s5p5 CAS number 7553-56-2

What is Iodine?

  • Iodine with the symbol ‘I’ is a dark gray or purple blackish nonmetallic element with atomic number 53 in the Periodic Table.
  • It is the least reactive and most electropositive halogen, even though it can form compounds with many elements.
  • It is mainly found on Earth as the water-soluble iodide in brine pools and oceans.
  • This element gives purple color when heated.
  • It is not completely soluble in water and dissolves in few solvents like carbon tetrachloride.
  • Iodine element is available naturally in air, soil, and water. The most important source of this element is oceans. There are even some minerals, which contain iodine in them.
  • Iodine is an essential component in humans for a proper functioning of the brain. The human body contains nearly 20 milligrams in the thyroid gland.

Uses or Applications of Iodine

  • First commercial use of iodine is Photography. Louis Daguerre invented a technique for producing images on a piece of metal.
  • It is used in pharmaceutical industry, printing industry and in the manufacturing of animal feed.
  • It is also used as the water purifier.
  • This element is used in almost all medicines that aid in cleaning wounds.

Environmental Effects of Iodine

  • Iodine present in the air combines with water particles and get dissolved into water or soils. Plants absorb the dissolved Iodine from water and soil in the process of their growth. Humans or animals get iodine from the plant sources. Iodine present or dissolved in water will evaporate and get mixed up in the air.
  • Iodine may be radioactive but it is not harmful to life.