isotope vs atom

isotope and atom both are nouns.

Word	Noun	Adjective	Verb	Adverb
isotope	Yes	No	No	No
atom	Yes	No	No	No

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

isotope: one of two or more atoms with the same atomic number but with different numbers of neutrons
atom: (physics and chemistry) the smallest component of an element having the chemical properties of the element

isotope (noun)	atom (noun)
one of two or more atoms with the same atomic number but with different numbers of neutrons	(physics and chemistry) the smallest component of an element having the chemical properties of the element
	(nontechnical usage) a tiny piece of anything