* Acids are liquids that donate protons (H+ ions) when dissolved in water. They are typically sour or acidic in taste and turn blue litmus paper red. Acids include hydrochloric acid, sulfuric acid, and nitric acid.

* Bases are liquids that accept protons (H+ ions) when dissolved in water. They are typically bitter or alkaline in taste and turn red litmus paper blue. Bases include sodium hydroxide, potassium hydroxide, and calcium hydroxide.

* Salts are compounds that are formed when an acid and a base react. They are typically neutral in taste and do not affect the color of litmus paper. Salts include sodium chloride, potassium sulfate, and calcium carbonate.