suspense vs doubtfulness

suspense and doubtfulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
suspense	Yes	No	No	No
doubtfulness	Yes	No	No	No

As nouns, doubtfulness is a hypernym of suspense; that is, doubtfulness is a word with a broader meaning than suspense:

Other hypernyms of suspense include doubt, dubiety, dubiousness, incertitude, uncertainty.

suspense (noun)	doubtfulness (noun)
an uncertain cognitive state	uncertainty about the truth or factuality or existence of something
excited anticipation of an approaching climax	the state of being unsure of something
apprehension about what is going to happen