acids and bases

Acids are compounds that tend to give up a hydrogen ion (H+). They are usually sour. They react with bases to form salt and water.

Bases are compounds that tend to receive a hydrogen ion (H+). They are usually bitter. They react with acids to form salt and water.

Indicators are compounds that slightly change their structure, and also their color, in the presence of acid or base.

Neutralization reaction is the reaction between an acid and a base, forming a salt and water.
There are numerous acids and bases in our household: vinegar, muriatic acid, car battery acid, lye, baking soda, spirit of ammonia

Acids in the atmosphere are usually produced by nitrogen oxides and sulfur oxides that are released into the atmosphere from the burning of fossil fuels. They may be carried to the ground by rain.