Wind insulated wire about 30 times around the length of a 3 or 4 inch soft iron nail. Connect the two ends of the wire to a battery; a 9-volt PP3 battery is perfect. Drop a few metal paper clips on a table, or use iron fillings. Put the end of the nail near the paper clips or iron fillings. The paper clips or iron fillings are drawn toward the nail and stick to it. This is because the electrical current flowing through the coil of wire has created a magnetic field that is transferred to the nail. Disconnect the wires from the battery. The paper clips or iron fillings fall off the nail because as the current stops, the soft iron nail is no longer magnetic.
You can use the same procedure to make a permanent magnet, but you need to use a steel nail rather than an iron nail. Wind insulated wire around the steel nail 30 times as before. Connect the ends of the wire to the battery, but this time leave it connected for several minutes. During this time, the magnetic field created by the coil of wire induces its force into the steel nail. Disconnect the battery. Put the end of the nail near the paper clips. The paper clips stick to the nail because it is a permanent magnet.
All magnets, including electromagnets have a north and south pole. One end of the nail you magnetized is a south pole and the other end a north pole. You can find out which end is north or south by using another permanent magnet that has the poles marked on it. Put one end of the nail toward the north pole on the other magnet. If the nail sticks to the magnet, that end of the nail is south as opposite attract; if it is repelled, that end of the nail is north. Mark each end of the nail. Note that while the nail has retained magnetism, it will gradually lose power over time.
A permanent magnet's poles always remain the same. However, you can change the poles on an electromagnet. Connect the wires from the coil of wire that's wrapped around the nail, but this time change the polarity. Connect the wire that was previously connected to the positive battery terminal onto the negative battery and vice versa for the other wire. Leave the current running for several minutes. The direction of the flow of current has changed and is going in the opposite direction as before. Disconnect the wires and put the end of the nail marked north near the south pole of the other permanent magnet. It is repelled because the electrical flow has altered the way the nail is magnetized.