* Water is an exception: Water is a unique substance because its solid form (ice) is less dense than its liquid form. This is why ice floats. So, when water freezes, its volume actually increases.

* Most other liquids: For most other liquids, freezing causes a decrease in volume. This is because the molecules in a solid are more tightly packed together than in a liquid.

Here's a simple analogy: Imagine a room full of people dancing. The people are like the molecules in a liquid, moving around freely. Now imagine everyone freezing in place. They'll take up less space because they're no longer moving.

Important note: The exact change in volume when a liquid freezes depends on the specific liquid and the freezing temperature.