impact vs excite

impact is a noun but excite is not a noun.

Word	Noun	Adjective	Verb	Adverb
impact	Yes	No	Yes	No
excite	No	No	Yes	No

As verbs, excite is a hyponym of impact; that is, excite is a word with a more specific, narrower meaning than impact:

impact (noun)	excite (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

impact (verb)	excite (verb)
have an effect upon	act as a stimulant
press or wedge together; pack together	produce a magnetic field in
	raise to a higher energy level
	stir the feelings, emotions, or peace of
	to evoke sexual feelings
	arouse or elicit a feeling
	cause to be agitated, excited, or roused
	stir feelings in