You're gobbling down the last of a candy bar when the coach calls your name. She asks you to pitch! You've only pitched during practice. You get so nervous that it upsets your stomach. Your stomach feels like it's on fire!

Too much acid in your stomach can cause it to be upset. When this happens, your parents may tell you to take an antacid.

Antacids can neutralize stomach acid because they contain a base. When you mix the right amounts of an acid and a base, they neutralize one another.