This is a fascinating aspect of water! Here's how the density changes when water goes from liquid to solid:

* Density decreases: Unlike most substances, water becomes *less* dense when it freezes into ice.

* The reason: This is due to the way water molecules arrange themselves. In liquid water, the molecules are relatively close together and can move around freely. However, as water freezes, the molecules form a crystalline structure with an open, hexagonal lattice. This lattice structure creates more space between the molecules, making ice less dense than liquid water.

* The consequence: This is why ice floats! Because it's less dense than liquid water, it displaces a volume of water equal to its own weight, allowing it to float.

Let me know if you'd like to explore other interesting properties of water!