tell on vs impact

tell on is not a noun while impact is a noun.

Word	Noun	Adjective	Verb	Adverb
tell on	No	No	Yes	No
impact	Yes	No	Yes	No

As verbs, impact is a hypernym of tell on; that is, impact is a word with a broader meaning than tell on:

Other hypernyms of tell on include affect, bear on, bear upon, touch, touch on.

tell on (noun)	impact (noun)
	influencing strongly
	the violent interaction of individuals or groups entering into combat
	the striking of one body against another
	a forceful consequence; a strong effect

tell on (verb)	impact (verb)
produce an effect or strain on somebody	have an effect upon
give away information about somebody	press or wedge together; pack together