What binds a sugar cube?

The binding force in a sugar cube is hydrogen bonding. Hydrogen bonding is an intermolecular force that occurs between a hydrogen atom bonded to a highly electronegative atom (such as oxygen, nitrogen, or fluorine) and another electronegative atom. In the case of a sugar cube, the hydrogen bonding occurs between the hydrogen atoms of the hydroxyl groups (-OH) of the sucrose molecules and the oxygen atoms of the water molecules. These hydrogen bonds create a network of intermolecular interactions that hold the sugar cube together and give it its solid structure.