chemical science vs critical

chemical science is a noun but critical is not a noun.

Word	Noun	Adjective	Verb	Adverb
chemical science	Yes	No	No	No
critical	No	Yes	No	No

chemical science (noun)	critical (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions

chemical science (adjective)	critical (adjective)
	marked by a tendency to find and call attention to errors and flaws
	characterized by careful evaluation and judgment
	being in or verging on a state of crisis or emergency
	at or of a point at which a property or phenomenon suffers an abrupt change especially having enough mass to sustain a chain reaction
	of or involving or characteristic of critics or criticism
	forming or having the nature of a turning point or crisis
	urgently needed; absolutely necessary