What type of bonds are being broken when you melt ice?
Hydrogen bonds. Hydrogen bonds are relatively weak bonds, and don't involve the sharing or transfer of electrons. The bond between each oxygen and hydrogen atom is a polar covalent bond, which involves the unequal sharing of electrons.
Water molecules are polar. The oxygen atom has a partial negative charge
The following diagram shows the hydrogen bonds that at its freezing point cause the water molecules to form a crystalline structure, increasing volume, and decreasing density. Water is at its lowest density at