Acids and Bases

Acids and bases are special kinds of substances. Acids often taste sour, like lemon juice. Bases often feel slippery, like soap. Scientists use a scale called pH to measure how strong they are.

Everyday Acids and Bases

You see acids and bases every day. Orange juice, vinegar, and soda are all acids. Soap, baking soda, and ammonia are bases. Pure water is in the middle, not an acid or a base. Your stomach has a strong acid that helps you digest food.

A model shows an acid mixing with water and changing.
A model shows an acid mixing with water and changing. (Ben Mills / Wikimedia Commons)

How They React

When you mix an acid with a base, they can cancel each other out. This is called neutralization. The result is often just water and a salt. People take antacid tablets when their stomach feels too sour. The tablet is a base that calms the acid.

Fun Facts

  • The pH scale goes from 0 to 14.
  • Battery acid is one of the strongest acids.
  • Red cabbage juice changes color in acids and bases.

Did You Know?

Bees sting with acid, but wasps sting with a base. That is why different stings can hurt in different ways.