Final answer:
pH is a measure of the acidity or basicity of a substance. Substances with pHs less than 7 are acidic, more than 7 are basic, and exactly 7 are neutral.
Step-by-step explanation:
In the context of chemistry and the study of pHs, one important concept is the classification of substances as acidic or basic, based on their pH values. The pH scale ranges from 0 to 14. Compounds that have a pH less than 7 are considered acidic. On the other hand, compounds that have a pH greater than 7 are considered basic. The mid-point of the pH scale, which is 7, represents a neutral pH. For instance, pure water at 25°C has a pH of 7 and it is neutral as it's neither acidic nor basic.
Learn more about pH scale