I understand the "north" is where to field is "coming out of" and south is where it returns, and i can see how two magnets would repel and attract. However when electrons or protons are brought near magnetic fields they are deflected. Why? What determines which direction a negativley charged particle would deflect towards? Is "south" negative and "north" positive? I cant seem to type this into google in a way that wouldnt bring up links to "magnets for kids" or similar.