Isotopes of Hydrogen

Isotopes of Hydrogen

Hydrogen has three isotopes: Protium, ¹₁H, deuterium, ²₁H or D and tritium, ³₁H or T. These isotopes differ from one another in respect of the presence of neutrons. Oridinary hydrogen, protium, has no neutrons, deuterium (also known as heavy hydrogen) has one and tritium has two neutrons in the nucleus. In the year 1934, an American scientist, Harold C, Urey, got Noble Prize for separation hydrogen isotope of mass number 2 by physical methods.

The predominant form is protium. Terrestrial hydrogen contains 0.0156% of deuterium mostly in the form of HD. The tritium concentration is about one atom per 10¹⁸ atoms of protium. Of these isotopes, only tritium is radioactive and emits low energy B^- particles.

Since the lsotopes have the same electronic configuration, they have almost the same chemical properties. The only difference is in their rates of reactions, mainly due to their different enthalpy of bonds dissociation. However, in physical properties these isotopes differ considerably due to their large mass differences.