What are collisions between molecules?

When molecules bump into each other, it’s called collisions between molecules, just like when you and your friend crash into each other on the playground.

Imagine you're playing tag in a big room full of kids. Everyone is running around, sometimes passing by each other, but often knocking into one another. That’s kind of what happens with molecules, tiny particles that are always moving, bouncing off each other as they zoom around inside things like air or water.

Think of molecules as little balls, like the ones you play with in a toy box. If you shake the box, those balls start to move and crash into each other. Every time two balls hit, it’s a collision. Sometimes they just bounce off quickly, and sometimes they might even change direction or speed up.

In the air we breathe, there are millions of these tiny “balls”, molecules like nitrogen and oxygen, all moving around and colliding with each other. These bumps keep them from just staying still; they’re always in motion because of these little crashes!