Eli5: Materials expand when heated and contracts when cooled. So why does water expand when it freezes instead of contracting?

Question

Eli5: Materials expand when heated and contracts when cooled. So why does water expand when it freezes instead of contracting?

In: 24

Answer 1

When most substances cool down, their molecules get closer and closer together and move less and less.

As water freezes, its state changes, and the hydrogen bonds create a lattice that makes unique geometric shapes, stopping the water molecules from getting close together.

You know how “every snowflake is a unique shape” this is becausevif this lattice effect.