chemical science vs indicator

chemical science and indicator both are nouns.

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

chemical science (noun)	indicator (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions	a device for showing the operating condition of some system
	a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time
	a signal for attracting attention
	(chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction