The classic example of a solid that floats easily in its liquid form is ice (solid water) in water.

Here's why:

* Water expands when it freezes: This is unusual for most substances. As water molecules cool and freeze, they form a crystal structure with more space between them, making ice less dense than liquid water.

* Density determines buoyancy: Objects less dense than the fluid they are in will float. Since ice is less dense than water, it floats.

Let me know if you'd like to explore other examples!