inactiveness vs inactivity

inactiveness and inactivity both are nouns.

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

As nouns, inactiveness and inactivity are synonyms defined as:

Other synonyms of inactiveness include inertia.

As nouns, inactiveness and inactivity are synonyms defined as:

Other synonyms of inactiveness include inaction.

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