*Sour Makes You Happy*

If you bite into a lemon, you’ll feel the sourness. The body cares about how acidic it is on the inside. The so-called pH level, a measure of acidity, is very precisely regulated in the blood; otherwise, we would find ourselves in a life-threatening situation. The reason is that if the pH level is incorrect, the building blocks in the blood and the body’s cells will function too quickly or too slowly—or be destroyed. Breathing and the kidneys work to maintain the exact pH level. In many laboratory experiments, too, the correct pH level is often of crucial importance. See how you can determine the pH level using simple and straightforward methods. You and your children can try it yourselves.