Acid

Definition

An acid is a substance that releases hydrogen ions (H+) when dissolved in water, characterized by a sour taste and the ability to turn blue litmus paper red. Acids play vital roles in various physiological processes, such as digestion and the maintenance of body pH.

Related terms

pH: A measure of how acidic or basic a solution is, on a scale ranging from 0 (most acidic) to 14 (most basic).

Hydrogen ion (H+): A positively charged ion or proton that acids release into solutions, which fundamentally contribute to the acidity of the solution.

Base: A substance that accepts hydrogen ions in solution and has a pH greater than 7; it turns red litmus paper blue and often feels slippery