atomic spectrum vs physics

atomic spectrum and physics both are nouns.

Word	Noun	Adjective	Verb	Adverb
atomic spectrum	Yes	No	No	No
physics	Yes	No	No	No

atomic spectrum (noun)	physics (noun)
(physics) a spectrum of radiation caused by electron transitions within an atom; the series of spectrum lines is characteristic of the element	the science of matter and energy and their interactions
	the physical properties, phenomena, and laws of something