hydrogen bomb vs atomic weapon

hydrogen bomb and atomic weapon both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydrogen bomb	Yes	No	No	No
atomic weapon	Yes	No	No	No

As nouns, atomic weapon is a hypernym of hydrogen bomb; that is, atomic weapon is a word with a broader meaning than hydrogen bomb:

hydrogen bomb: a nuclear weapon that releases atomic energy by union of light (hydrogen) nuclei at high temperatures to form helium
atomic weapon: a weapon of mass destruction whose explosive power derives from a nuclear reaction

Other hypernyms of hydrogen bomb include bomb, nuclear weapon.

hydrogen bomb (noun)	atomic weapon (noun)
a nuclear weapon that releases atomic energy by union of light (hydrogen) nuclei at high temperatures to form helium	a weapon of mass destruction whose explosive power derives from a nuclear reaction