important vs importance

important is not a noun while importance is a noun.

Word	Noun	Adjective	Verb	Adverb
important	No	Yes	No	No
importance	Yes	No	No	No

important (noun)	importance (noun)
	the quality of being important and worthy of note
	a prominent status

important (adjective)	importance (adjective)
of great significance or value
of extreme importance; vital to the resolution of a crisis
important in effect or meaning
having or suggesting a consciousness of high position
having authority or ascendancy or influence