Science Common Sense

1565 - Why does air cool down as it rises due to expansion?

Imagine you're blowing up a balloon. As you blow more air into it, the balloon expands and gets bigger. When air rises, it expands because the air pressure above it is lower. This expansion makes the air molecules move away from each other.

When these air molecules move away, they don't collide as much as they used to, which makes them lose some of their energy. Losing energy means they start moving slower, and when they move slower, the air gets cooler. That's why air cools down as it rises due to expansion.