expansivity vs expansive

expansivity is a noun but expansive is not a noun.

Word	Noun	Adjective	Verb	Adverb
expansivity	Yes	No	No	No
expansive	No	Yes	No	No

expansivity (noun)	expansive (noun)
a friendly open trait of a talkative person
a quality characterized by magnificence of scale or the tendency to expand
the fractional change in length or area or volume per unit change in temperature at a given constant pressure

expansivity (adjective)	expansive (adjective)
	able or tending to expand or characterized by expansion
	friendly and open and willing to talk
	marked by exaggerated feelings of euphoria and delusions of grandeur
	of behavior that is impressive and ambitious in scale or scope