Mention the uses of heavy water .

Explanation

(i) Heavy water is used as moderator in nuclear reactors as it can lower the energies of fast moving neutrons.
(ii) `D_(2)O` is commonly used as an tracer to study organic reaction mechanisms and mechanisms of metabolic reactions.
(iii) It is also used as a coolant in muclear reactors as it absorbs the heart generated.
`{:(A,"Deuterium",D_(2)),(B,"Heavy water",D_(2)O),(C,"Propane",C_(3)H_(6)),(D,"Deuteron propane",C_(3)D_(6)):}`