intellectual vs mental

intellectual is a noun but mental is not a noun.

Word	Noun	Adjective	Verb	Adverb
intellectual	Yes	Yes	No	No
mental	No	Yes	No	No

intellectual (noun)	mental (noun)
a person who uses the mind creatively

intellectual (adjective)	mental (adjective)
appealing to or using the intellect	involving the mind or an intellectual process
involving intelligence rather than emotions or instinct	of or relating to the mind
of or associated with or requiring the use of the mind	of or relating to the chin- or liplike structure in insects and certain mollusks
	of or relating to the chin or median part of the lower jaw
	affected by a disorder of the mind