pH scale vs chemistry

pH scale and chemistry both are nouns.

Word	Noun	Adjective	Verb	Adverb
pH scale	Yes	No	No	No
chemistry	Yes	No	No	No

pH scale (noun)	chemistry (noun)
(from potential of Hydrogen) the logarithm of the reciprocal of hydrogen-ion concentration in gram atoms per liter; provides a measure on a scale from 0 to 14 of the acidity or alkalinity of a solution (where 7 is neutral and greater than 7 is more basic and less than 7 is more acidic)	the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
	the way two individuals relate to each other
	the chemical composition and properties of a substance or object