That's a common misconception! Ice actually has a *lower* density than water. This is why ice floats.

Here's why:

* Water molecules form a crystal structure in ice. The hydrogen bonds between water molecules create a very open, hexagonal structure in ice.

* This structure leaves more space between the molecules. In liquid water, molecules are more closely packed.

* Less density means less mass per unit volume. Since ice has a more open structure, it has a lower density than liquid water.

This unusual property of water is crucial for life on Earth:

* Ice insulates water. The layer of ice that forms on lakes and ponds prevents the water below from freezing solid, allowing aquatic life to survive.

* Ice helps regulate Earth's climate. Ice reflects sunlight, helping to keep the planet cool.

Let me know if you have any other questions about water and ice!