chemical science vs pH scale

chemical science and pH scale both are nouns.

Word	Noun	Adjective	Verb	Adverb
chemical science	Yes	No	No	No
pH scale	Yes	No	No	No

chemical science (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)