reasonable vs rational

reasonable is not a noun while rational is a noun.

Word	Noun	Adjective	Verb	Adverb
reasonable	No	Yes	No	No
rational	Yes	Yes	No	No

reasonable (noun)	rational (noun)
	an integer or a fraction

reasonable (adjective)	rational (adjective)
showing reason or sound judgment	consistent with or based on or using reason
not excessive or extreme	capable of being expressed as a quotient of integers
marked by sound judgment; having good reason	having its source in or being guided by the intellect (as distinguished from experience or emotion)
	of or associated with or requiring the use of the mind