deuterium vs heavy hydrogen

deuterium and heavy hydrogen both are nouns.

Word	Noun	Adjective	Verb	Adverb
deuterium	Yes	No	No	No
heavy hydrogen	Yes	No	No	No

As nouns, deuterium and heavy hydrogen are synonyms defined as:

deuterium and heavy hydrogen: an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)

deuterium (noun)	heavy hydrogen (noun)
an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)	an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)