nuclear physicist vs J. Robert Oppenheimer

nuclear physicist and J. Robert Oppenheimer both are nouns.

Word	Noun	Adjective	Verb	Adverb
nuclear physicist	Yes	No	No	No
J. Robert Oppenheimer	Yes	No	No	No

nuclear physicist (noun)	J. Robert Oppenheimer (noun)
a physicist who specializes in nuclear physics	United States physicist who directed the project at Los Alamos that developed the first atomic bomb (1904-1967)