Solvents are substances that can dissolve other substances.Water can act as a solvent for ions (charged particles/molecules) because it is dipolar (the positive electrons from the 2x hydrogen are pulled towards the oxygen end making the oxygen end slightly negative and the lack of electrons on the hydrogen end makes that side slightly positive).Ions are charged particles therefore positive ions will be attracted to the slightly negative Oxygen end of the water molecule and the negative ions will be attracted to the slightly positive hydrogen end of the molecule. The ions will get totally surrounded by the water molecule and dissolve.