expansivity vs impressiveness

expansivity and impressiveness both are nouns.

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

As nouns, impressiveness is a hypernym of expansivity; that is, impressiveness is a word with a broader meaning than expansivity:

expansivity: a quality characterized by magnificence of scale or the tendency to expand
impressiveness: splendid or imposing in size or appearance

Other hypernyms of expansivity include grandness, magnificence, richness.

expansivity (noun)	impressiveness (noun)
a friendly open trait of a talkative person	splendid or imposing in size or appearance
a quality characterized by magnificence of scale or the tendency to expand	the quality of making a strong or vivid impression on the mind
the fractional change in length or area or volume per unit change in temperature at a given constant pressure