reflectiveness vs reflectivity

reflectiveness and reflectivity both are nouns.

Word	Noun	Adjective	Verb	Adverb
reflectiveness	Yes	No	No	No
reflectivity	Yes	No	No	No

As nouns, reflectiveness and reflectivity are synonyms defined as:

reflectiveness and reflectivity: the capability of quiet thought or contemplation

reflectiveness (noun)	reflectivity (noun)
the capability of quiet thought or contemplation	the ability to reflect beams or rays
	the capability of quiet thought or contemplation
	the fraction of radiant energy that is reflected from a surface