chemical notation vs notation

chemical notation and notation both are nouns.

Word	Noun	Adjective	Verb	Adverb
chemical notation	Yes	No	No	No
notation	Yes	No	No	No

As nouns, notation is a hypernym of chemical notation; that is, notation is a word with a broader meaning than chemical notation:

chemical notation: a notation used by chemists to express technical facts in chemistry
notation: a technical system of symbols used to represent special things

Other hypernyms of chemical notation include notational system.

chemical notation (noun)	notation (noun)
a notation used by chemists to express technical facts in chemistry	the activity of representing something by a special system of marks or characters
	a technical system of symbols used to represent special things
	a comment or instruction (usually added)