Describe magnets as having two poles (north and south) and predict whether two magnets will attract or repel based on which poles face each other
Every magnet has two ends. One end is called the north pole. The other end is called the south pole. We write N for north and S for south. A magnet's pull is strongest right at its poles.
Magnets follow one simple rule. Like poles repel, so two poles that are the same push each other away. Opposite poles attract, so a north pole and a south pole pull toward each other.
Mia holds two bar magnets with N facing out on both. When she brings the two N ends close, they push apart. Then she flips one magnet around, so N faces S. Now the magnets snap together.
Before you bring two magnets together, check the letters on each end. Same letters facing each other means push apart. Different letters facing each other means pull together.
Every magnet has a north pole and a south pole: like poles push apart, and opposite poles pull together.
Magnets are like invisible push and pull machines. Every magnet has two ends called poles: a north pole and a south pole. If you hold a magnet by its middle and let it swing freely, the north pole will point toward Earth's geographic north. That is because Earth itself acts like a giant magnet.
When you bring two magnets close together, they either snap together or push apart. Opposite poles attract, north pulls south. Like poles repel, north pushes north, south pushes south. You can feel this push and pull without the magnets even touching. The magnetic force works through air, paper, even your hand. Try putting a magnet under a piece of paper with iron filings on top. The filings line up in curved lines showing the invisible magnetic field stretching between the poles.
A magnet never comes with just one pole. Break a bar magnet in half and you get two smaller magnets, each with its own north and south. Keep breaking the pieces and each tiny fragment still has both poles. There is no such thing as a lone north pole or a lone south pole, what scientists call a magnetic monopole. This is one of the first big rules of magnetism.
Magnets attract certain metals like iron, nickel, and cobalt. Your fridge door is steel, so a magnet sticks to it. But a magnet will not stick to aluminum foil, copper wire, or a plastic toy. The difference is in the atoms. In magnetic materials, tiny atomic magnets line up in the same direction. In non-magnetic materials, they point every which way and cancel out.
You can make a temporary magnet by stroking a nail with a permanent magnet, always in the same direction. The nail's atoms line up and it becomes magnetic for a while. Hit the nail with a hammer or heat it up and the atoms get jumbled again. The magnetism fades. This is called demagnetization.
You can also make an electromagnet by wrapping wire around an iron nail and connecting it to a battery. Electric current creates a magnetic field. The more loops of wire, the stronger the magnet. Turn off the current and the magnetism stops instantly. Electromagnets lift cars in junkyards and make doorbells ring.
Last time, Grace tested things around her house and found a magnet only pulls special materials like iron, steel, nickel, and cobalt. Today Mia is holding two bar magnets, and every magnet has two ends with special names.
What are the two ends of a magnet called?
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