Regarding your magnet question, I found this at Questions and Answers - What happens when a magnet is cut in two? Does the strength of an electromagnet depend on the number of turns of wire? If you have two magnets...Since the magnet is now two different poled magnets, even if you put them back together visibly, they will not have the same characteristics as a single magnet would. I don't know how much this would affect things at this level, but you are probably best served with the new ones.A couple of different things can happen when you cut a magnet in half.If you do it gently you can end up with two magnets. You can think of a magnet as a bundle of tiny magnets, called magnetic domains, that are jammed together. Each one reinforces the magnetic fields of the others. Each one has a tiny north and south pole. If you cut one in half, the newly cut faces will become the new north or south poles of the smaller pieces. You could keep slicing smaller and smaller slices like a loaf of bread and keep getting thinner magnets, each with a new set of poles. Remember, I did say though you only get two magnets if you cut them gently. The magnetic domains in a magnetic material can be knocked loose, by bumping or vibrating the magnet (like when sawing it in half). If knocked loose, the domains are no longer arranged neatly, so they do not reinforce each other. If they are in a random orientation, with their fields pointing all over the place, they cancel each other out.