niceness vs nice

niceness is a noun but nice is not a noun.

Word	Noun	Adjective	Verb	Adverb
niceness	Yes	No	No	No
nice	No	Yes	No	No

niceness (noun)	nice (noun)
the quality of nice
the quality of being difficult to detect or analyze
a courteous manner that respects accepted social usage

niceness (adjective)	nice (adjective)
	pleasant or pleasing or agreeable in nature or appearance
	excessively fastidious and easily disgusted
	exhibiting courtesy and politeness
	socially or conventionally correct; refined or virtuous
	done with delicacy and skill