unsubstantial vs solidness

unsubstantial is not a noun while solidness is a noun.

Word	Noun	Adjective	Verb	Adverb
unsubstantial	No	Yes	No	No
solidness	Yes	No	No	No

unsubstantial (noun)	solidness (noun)
	the quality of being substantial or having substance
	the quality of being solid and reliable financially or factually or morally
	the consistency of a solid
	the state in which a substance has no tendency to flow under moderate stress; resists forces (such as compression) that tend to deform it; and retains a definite size and shape

unsubstantial (adjective)	solidness (adjective)
lacking material form or substance; unreal