deuterium vs hydrogen atom

deuterium and hydrogen atom both are nouns.

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

As nouns, hydrogen atom is a hypernym of deuterium; that is, hydrogen atom is a word with a broader meaning than deuterium:

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

Other hypernyms of deuterium include isotope.

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