metastable vs physics

metastable is not a noun while physics is a noun.

Word	Noun	Adjective	Verb	Adverb
metastable	No	Yes	No	No
physics	Yes	No	No	No

metastable (noun)	physics (noun)
	the science of matter and energy and their interactions
	the physical properties, phenomena, and laws of something

metastable (adjective)	physics (adjective)
(of physical systems) continuing in its present state of equilibrium unless sufficiently disturbed to pass to a more stable state of equilibrium