What causes the distinct smell of ozone after lightning?

The smell after lightning is caused by ozone, which is made when lightning zaps the air around it.

Ozone is like a supercharged version of oxygen, the stuff we breathe every day. Oxygen has two atoms, but ozone has three! When lightning hits the sky, it gives the air a big shock, breaking apart some oxygen molecules into single atoms. These atoms then team up with other oxygen molecules to form ozone.

Ozone has a special smell, kind of like a fresh, clean, or even a little sharp scent. Think about when you walk into a newly cleaned room after it’s been aired out, that’s kind of what ozone smells like. The lightning is like a giant vacuum cleaner for the air, making this new smell pop up all around us.

So next time you hear thunder and see lightning, remember: it's not just a show in the sky, it's also making ozone and giving the air a fresh, special scent!