impulse vs whim

impulse and whim both are nouns.

Word	Noun	Adjective	Verb	Adverb
impulse	Yes	No	No	No
whim	Yes	No	No	No

As nouns, impulse and whim are synonyms defined as:

Other synonyms of impulse include caprice.

impulse (noun)	whim (noun)
the act of applying force suddenly	an odd or fanciful or capricious idea
an impelling force or strength	a sudden desire
the electrical discharge that travels along a nerve fiber
(electronics) a sharp transient wave in the normal electrical state (or a series of such transients)
a sudden desire
an instinctive motive