law of reciprocal proportions vs chemical science

law of reciprocal proportions and chemical science both are nouns.

Word	Noun	Adjective	Verb	Adverb
law of reciprocal proportions	Yes	No	No	No
chemical science	Yes	No	No	No

law of reciprocal proportions (noun)	chemical science (noun)
(chemistry) law stating that the proportions in which two elements separately combine with a third element are also the proportions in which they combine together	the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions