chemistry vs pH scale

chemistry and pH scale both are nouns.

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

chemistry (noun)	pH scale (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions	(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 way two individuals relate to each other
the chemical composition and properties of a substance or object