chemical science vs decompose

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

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

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

chemical science (verb)	decompose (verb)
	separate (substances) into constituent elements or parts
	break down
	lose a stored charge, magnetic flux, or current