susceptibleness vs susceptible

susceptibleness is a noun but susceptible is not a noun.

Word	Noun	Adjective	Verb	Adverb
susceptibleness	Yes	No	No	No
susceptible	No	Yes	No	No

susceptibleness (noun)	susceptible (noun)
the state of being susceptible; easily affected

susceptibleness (adjective)	susceptible (adjective)
	(often followed by `of' or `to') yielding readily to or capable of
	easily impressed emotionally