Sodium chloride is an ionic compound. You see: Atoms have a neutral charge--they have the same number of negatively charged electrons and positively charged protons. If they lose an electron, then it throws off the balance and, lacking a negative particle, becomes positively charged. (Vice versa if it gains an electron.) When this happens, and the atom has an overall charge, it's called an ion. (Metals, btw, lose electrons, gaining a positive charge as ions, and non-metals gain electrons gaining a negative charge, so: metals = positive ions, non-metals = negative ions.) So, if you have a metallic ion like SODIUM with a + charge and a non-metallic ion like CHLORINE with a - charge, then since like attracts like, they'll stick together. That's an ionic bond. Now since the two nuclei don't share electrons like in a covalent bond... they're just stuck together like 2 reversed polar magnets... all you need is something magnetic to yank them apart. And so we come to water. A water molecule has a big oxygen atom with 2 little hydrogen atoms bonded to it. The hydrogens never bond directly across from each other on the oxygen, so it forms a triangle... with the oxygen at one vertex and the hydrogens at the other vertices. So, the water molecule ends up having an overall negative charge on the oxygen end, and an overall positive charge at the hydrogen end. It's what we call a polar molecule. So, you dump some ionically bonded sodium chloride into some polar water molecules, and... the charged ends of the water molecules rip the sodium ions from the sodium chloride (putting them at the negative end of the water molecule, since sodium ion is positive and oxygen end of water is negative, and opposites attract. (And naturally, the negative chlorine ion goes to the positive hydrogen end.) The water molecules rearrange them selves with the sodium ions and the chlorine ions to make a lattice that keeps everything nice and segregated, which we call a solution. Water does this with any ionic compound, which makes it the "universal solvent" and makes it an essential chemical background for so many processes in organic chemistry. (Incidentally, pure water, which never exists on Earth naturally... cuz it likes to eat stuff up in this way... is one of the most aggressive acids out there. Most people don't think of water that way.) Hope that helped!