Why does a magnet grab the stick between my toy car's wheels, not its plastic roof?

Picture a little toy car resting on the soft rug. Now you hold a magnet just above it. Click! Can you hear it? The car jumps up and hangs from the magnet.

Look closely and you will spot something funny. The magnet holds the thin rod between the wheels. That rod is the axle. So why does a magnet grab the axle, and not the plastic roof?

A magnet has a hidden pull. You cannot see it, but you can feel it tug. It reaches out a little way through the air and draws some things close without touching them. That pull is what made the car jump up.

The magnet does not pull on everything around it. Its pull grabs only things with iron in them. Iron is a strong grey metal, like the metal inside nails and screws.

The axle has iron inside it. So the magnet's pull grabs the axle and holds on tight. That is why the whole car lifts up, hanging by its axle.

Now let's look at the roof. The roof is plastic, smooth and light, just like your bath toys. What do you think, does plastic have any iron inside?

Plastic has no iron at all. So the magnet's pull finds nothing to grab there. The magnet can touch the roof, but it cannot hold on. That is why a magnet slides off the plastic roof.

One word helps us remember: iron. A magnet pulls on iron, the axle has iron, and plastic has none.

Sleep well, little explorer, and keep wondering about the world around you.