Acids have a pH below 7.0. Acids turn litmus paper red as they have pH below 7.0. Bases on the other hand have pH above 7.0. Water has a neutral pH of 7.0.
Acids have a sour taste. For example citric acids found in lemons make it sour. Vinegar has acetic acid which makes it sour.
Acids dissolve metals to form salts and hydrogen gas
