final vs unalterable

final is a noun but unalterable is not a noun.

Word	Noun	Adjective	Verb	Adverb
final	Yes	Yes	No	No
unalterable	No	Yes	No	No

final (noun)	unalterable (noun)
an examination administered at the end of an academic term
the final match between the winners of all previous matches in an elimination tournament

final (adjective)	unalterable (adjective)
occurring at or forming an end or termination	not capable of being changed or altered
conclusive in a process or progression	of a sentence; that cannot be changed
not to be altered or undone	remaining the same for indefinitely long times