What is an acid?
An acid is a chemical substance whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals (like calcium) to form salts. Aqueous solutions of acids have a pH of less than 7.
A lower pH means a higher acidity, and thus a higher concentration of hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic.
The definition of an acid is ; substance that can give protons