identity vs identical

identity is a noun but identical is not a noun.

Word	Noun	Adjective	Verb	Adverb
identity	Yes	No	No	No
identical	No	Yes	No	No

identity (noun)	identical (noun)
the distinct personality of an individual regarded as a persisting entity
exact sameness
the individual characteristics by which a thing or person is recognized or known
an operator that leaves unchanged the element on which it operates

identity (adjective)	identical (adjective)
	(of twins) derived from a single egg or ovum
	coinciding exactly when superimposed
	having properties with uniform values along all axes
	exactly alike; incapable of being perceived as different
	being the exact same one; not any other: