Acids & Bases

Lemon juice puckers your mouth. Soap is slick between your fingers. Pure water sits quietly in the middle. These are the fingerprints of acids and bases — and chemistry pins each one to a precise spot on a single scale.

That scale is pH. It runs from 0 to 14, and it all comes down to one thing: how many hydrogen ions (H⁺) are floating in the solution.