significant vs significance

significant is not a noun while significance is a noun.

Word	Noun	Adjective	Verb	Adverb
significant	No	Yes	No	No
significance	Yes	No	No	No

significant (noun)	significance (noun)
	the quality of being significant
	a meaning that is not expressly stated but can be inferred
	the message that is intended or expressed or signified

significant (adjective)	significance (adjective)
important in effect or meaning
too closely correlated to be attributed to chance and therefore indicating a systematic relation
of considerable importance, size, or worth
rich in significance or implication