What type of chemical bonds are broken when ice is melted?
To follow up on what Paul has said, you need to understand the difference between the bonds within a molecule and the intermolecular attractions that exist BETWEEN molecules. It is the intermolecular attractions that determine if a substance is solid, liquid or gas. The change in state does NOT alter the internal chemical bonds between oxygen and hydrogen. Your answer choices are somewhat misleading since “ionic”, “nonpolar covalent”, and “polar covalent” are all internal (intramolecuar) bonds. Only “hydrogen bond” is the intermolecular bond. Water molecules contain polar covalent bonds between the oxygen and hydrogen atoms. These are intramolecular bonds. Water also exhibits a strong attraction between water molecules where the hydrogen of one molecule shares an attraction with the oxygen of an adjacent molecule. This is the hydrogen bonding to which Paul was referring. When water changes phases, it is these intermolecular hydrogen bonds which may be broken.
