Isotopes of hydrogen


There are three isotopes of hydrogen. These are deuterium, protium and tritium. The isotopes of hydrogen have different chemical and physical properties. These differences are greater in hydrogen than in any other element.

Property Protium Deuterium Tritium
Symbols 1H and H 2H and D 3H and T
Isotopic mass 1.0078 2.0141 3.0160
Natural abundance 99.985% 0.0156% < 1 in 1017 atoms
Nuclear spin 1/2 1 1/2

The reason for the difference in the chemical and physical properties between Hydrogen, Deuterium and tritium is due to the difference in mass. This difference in mass affects the fundamental vibrational wave numbers and the zero point energies

Deuterium

Deuterium was first discovered in 1932 by the American chemist Harold C. Urey. It is a stable isotope at room tempture and normal pressure. It is used in chemistry and industy in compounds. Compounds containing deuterium have a variety of purposes the effect of fully deuterated material can have a significant effect on the properties of the compound for example in H20 as it produce heavy water and in nuclure bombs.

Property H2O D20
Melting point - K 273.0 276.7
Boiling point – K 373.0 374.4
Density – g cm-3 0.999 1.105
Kw (at 298) 1 x 10-14 2 x 10-15
Symmetric strectch 3657 52671

These difference give deuterated compounds uses in industry . It is used as heavy water d2o (h2o) in nuclear reactors. Deuterium has a lower cross-section for neutron capture the 1hydrogen. This makes d2o a suitable material for reducing the energies of fast neutrons produced on fusion without appreciably diminishing the neutron flux.

Tritium

This is the third isotope of hydrogen it contains one proton one electron and two neutrons. It was discovered in 1934 by hitting a deuterium atom with a deuterium nuclei. This is a radioactive and has a half life of 12.4 years. It is possible to make tritium in the laboratory by using a nuclear reaction. Due to it short half life and the fact it is a weak ß-emitter it is used as a tracer. This tracer is used in chemical and biological stuieds

Production and uses of hydrogen History of hydrogen Home
Author: James Guscott(document modification date: 22nd may 2003)