The nuclear chemistry is a field of the Chimie treating Radioactivité, processes and properties nuclear. It is divided into five subcategories:

• the Radiochimie treats use of the radioactivity to study ordinary chemical reactions.
• the application of techniques resulting from chemistry to study nuclear reactions such as the fission and the fusion — to also see Nuclear physics.
• the isotopic chemistry treats influence of the Atomic mass of the elements on the chemical reactions and the properties of the chemical compounds (see isotopic Effet).
• the nuclear Spectroscopie of Magnetic resonance (NMR) uses the magnetic Moment of spin of the core of an element in order to determine the presence, the quantity and the environment of this element in a molecule, by nuclear transitions between levels from different energy.
• the chemistry which relates to the cycle of the Fuel nuclear, such as for example the processes of Retraitement nuclear.

The mechanism of a chemical reaction can be studied while observing as evolves/moves the kinetics of reaction when one of the atoms of the substrate was replaced by one of its isotopes. It is about a standard method in organic chemistry very much used nowadays. Briefly, the replacement of a hydrogen proton atom by a deuterium atom can bring a fall the reaction speed if the stage kinetically determining brings into play the rupture of a bond between hydrogen and another atom. Thus if the reaction speed is modified when the protons are replaced by deuteriums, it is reasonable to think that the stage kinetically determining comprises the rupture of a bond between a hydrogen and another atom.