law of conservation of matter vs conservation of matter

law of conservation of matter and conservation of matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
law of conservation of matter	Yes	No	No	No
conservation of matter	Yes	No	No	No

As nouns, law of conservation of matter and conservation of matter are synonyms defined as:

law of conservation of matter and conservation of matter: a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system

Other synonyms of law of conservation of matter include conservation of mass, law of conservation of mass.

law of conservation of matter (noun)	conservation of matter (noun)
a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system	a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system