Hydrochloric acid is a powerful chemical made of hydrogen and chlorine dissolved in water. It's so strong that it can dissolve some metals and burn through many materials, which is why scientists handle it carefully with gloves and safety goggles in laboratories.

Surprisingly, your stomach produces hydrochloric acid naturally every time you eat. The acid in your stomach isn't as concentrated as the kind in labs, but it's strong enough to help break down food and kill many harmful bacteria. Your stomach has a special protective lining that keeps the acid from digesting your own body, which is pretty remarkable when you think about it.

In factories, hydrochloric acid helps manufacture everything from fertilizers to cleaning products. It can remove rust from metal and is used in some products that help keep swimming pools clean. Scientists use it in experiments because it reacts predictably with many substances, making it useful for testing what things are made of. The acid produces distinctive fizzing and bubbling when it touches certain materials, like limestone or chalk, which helps geologists identify rocks.