emphasize vs emphasis

emphasize is not a noun while emphasis is a noun.

Word	Noun	Adjective	Verb	Adverb
emphasize	No	No	Yes	No
emphasis	Yes	No	No	No

emphasize (noun)	emphasis (noun)
	intensity or forcefulness of expression
	the relative prominence of a syllable or musical note (especially with regard to stress or pitch)
	special and significant stress by means of position or repetition e.g.
	special importance or significance

emphasize (verb)	emphasis (verb)
to stress, single out as important
give extra weight to (a communication)