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Why Does Ice Float?

This Science Minute was researched and written by Rachel S., Rome, NY.

Plop! Plop! You drop some ice cubes into your glass of lemonade, and they float to the top. Why does ice float, anyway?

To answer this, we need to think about the molecules that make up water. Usually, when a substance gets colder, its molecules get closer together. But water is different from most other solids. When water gets colder, its molecules spread apart. You've experienced this if you've ever put a glass bottle in the freezer overnight and had it explode!

Another way to say this is that water becomes less dense as it freezes. And because ice is less dense than water, it floats.