impulsive vs impulsiveness

impulsive is not a noun while impulsiveness is a noun.

Word	Noun	Adjective	Verb	Adverb
impulsive	No	Yes	No	No
impulsiveness	Yes	No	No	No

impulsive (noun)	impulsiveness (noun)
	the trait of acting suddenly on impulse without reflection

impulsive (adjective)	impulsiveness (adjective)
determined by chance or impulse or whim rather than by necessity or reason
having the power of driving or impelling
characterized by undue haste and lack of thought or deliberation
proceeding from natural feeling or impulse without external stimulus
without forethought