What is special about waters density when it is a solid?

Waters Density it solid state is less than its density at liquid state. That is why I’ve floats.

Also, fun fact:
ice expands when it freezes, which is the opposite of what most other materials do.

This is what i found “nuclear fuel is material used in nuclear power stations to produce heat to power turbines. heat is created when nuclear fuel undergoes nuclear fission. most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission.” i hope this you for what your looking for. can you plz mark me brainliest?

How do we find the answer?