careful vs carefulness

careful is not a noun while carefulness is a noun.

Word	Noun	Adjective	Verb	Adverb
careful	No	Yes	No	No
carefulness	Yes	No	No	No

careful (noun)	carefulness (noun)
	the quality of being careful and painstaking
	the trait of being cautious; being attentive to possible danger

careful (adjective)	carefulness (adjective)
exercising caution or showing care or attention
cautiously attentive
mindful of the future in spending money
full of cares or anxiety
unhurried and with care and dignity