nuclear physicist vs Arthur Compton

nuclear physicist and Arthur Compton both are nouns.

Word	Noun	Adjective	Verb	Adverb
nuclear physicist	Yes	No	No	No
Arthur Compton	Yes	No	No	No

nuclear physicist (noun)	Arthur Compton (noun)
a physicist who specializes in nuclear physics	United States physicist noted for research on x-rays and gamma rays and nuclear energy; his observation that X-rays behave like miniature bowling balls in their interactions with electrons provided evidence for the quantal nature of light (1892-1962)