inattentiveness vs heedlessness

inattentiveness and heedlessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
inattentiveness	Yes	No	No	No
heedlessness	Yes	No	No	No

As nouns, inattentiveness and heedlessness are synonyms defined as:

inattentiveness and heedlessness: a lack of attentiveness (as to children or helpless people)

inattentiveness (noun)	heedlessness (noun)
the trait of not being considerate and thoughtful of others	the trait of forgetting or ignoring your responsibilities
a lack of attentiveness (as to children or helpless people)	the trait of acting rashly and without prudence
	a lack of attentiveness (as to children or helpless people)