When you have a long wire and you put a metal object like a nail near the end of the wire, it will conduct electricity. This is because metals are good conductors of electricity. There are certain forces that move electrons from one atom to another. In some cases, atoms lose their electrons and become positively charged ions (examples of these situations are when an atom becomes molten or solidifies). The positively charged ions then move towards atoms with less positive charge on them, which gives an electron to those atoms.