unstable vs explosive

unstable is not a noun while explosive is a noun.

Word	Noun	Adjective	Verb	Adverb
unstable	No	Yes	No	No
explosive	Yes	Yes	No	No

unstable (noun)	explosive (noun)
	a chemical substance that undergoes a rapid chemical change (with the production of gas) on being heated or struck

unstable (adjective)	explosive (adjective)
lacking stability or fixity or firmness	serving to explode or characterized by explosion or sudden outburst
subject to change; variable	sudden and loud
suffering from severe mental illness	liable to lead to sudden change or violence
disposed to psychological variability
highly or violently reactive
affording no ease or reassurance