inactivity vs inactiveness

inactivity and inactiveness both are nouns.

Word	Noun	Adjective	Verb	Adverb
inactivity	Yes	No	No	No
inactiveness	Yes	No	No	No

As nouns, inactivity and inactiveness are synonyms defined as:

Other synonyms of inactivity include inertia.

As nouns, inactivity and inactiveness are synonyms defined as:

Other synonyms of inactivity include inaction.

inactivity (noun)	inactiveness (noun)
being inactive; being less active	a disposition to remain inactive or inert
a disposition to remain inactive or inert	the state of being inactive
the state of being inactive