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

not only water but some other like silicon.
water **also expands** when heated and the energy make the atoms move. when you are referring to ‘water’ I believe you are talking about water at room temp.
what causes water to **also expand when it freezes** is the fact that when this happens the structure of the material (lattice) prevents atom from being as close as at room temp.