validness vs validity

validness and validity both are nouns.

Word	Noun	Adjective	Verb	Adverb
validness	Yes	No	No	No
validity	Yes	No	No	No

As nouns, validness and validity are synonyms defined as:

validness and validity: the quality of having legal force or effectiveness

validness (noun)	validity (noun)
the quality of having legal force or effectiveness	the quality of having legal force or effectiveness
	the quality of being valid and rigorous