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Discovering which materials are attracted to magnets and which are not.
Imagine you have a superpower that lets you move objects without even touching them! Did you know that magnets use an invisible 'invisible hand' to pull things from across a room?
A magnet is a special object that can pull on certain types of metal. When a magnet pulls an object toward it, we call this attraction. Think of it like a sticky force that doesn't use glue! However, magnets are picky. They don't stick to everything. They only like materials that contain specific metals like iron, nickel, or cobalt. Most of the magnetic things you find around your house, like a refrigerator door or a paperclip, are made of steel, which has a lot of iron in it.
Quick Check
If you put a magnet near a plastic toy, will it stick?
Answer
No, because plastic does not contain magnetic metals like iron.
Magnets have a secret power: they don't have to touch an object to move it! Every magnet is surrounded by an invisible area called a magnetic field. This field is like an invisible bubble. If a magnetic object, like a staple, enters this bubble, the magnet will grab it. The closer the object gets to the magnet, the stronger the pull becomes. If you have magnets, you can even feel them pushing or pulling each other before they even touch!
Let's see the magnetic field in action: 1. Place a steel paperclip on a table. 2. Hold your magnet centimeters away. 3. Slowly slide the magnet closer: cm... cm... cm... 4. Suddenly, the paperclip will 'jump' to the magnet! This happens the moment the paperclip enters the magnetic field.
Quick Check
What do we call the invisible 'bubble' around a magnet where it can pull objects?
Answer
The magnetic field.
A common mistake is thinking that all metals are magnetic. This is a myth! While metals like iron and steel are very magnetic, many other metals are not. For example, aluminum (used in soda cans), copper (used in pennies), and gold (used in jewelry) are non-magnetic. This means a magnet will not pull on them at all. Scientists use magnets to sort trash by pulling out the iron and steel while leaving the aluminum and plastic behind.
Imagine you have a pile of items: a silver spoon (made of steel), an aluminum foil sheet, and a copper penny. 1. You touch the magnet to the spoon: It sticks! (Steel contains iron). 2. You touch the magnet to the foil: Nothing happens. (Aluminum is non-magnetic). 3. You touch the magnet to the penny: Nothing happens. (Copper is non-magnetic).
You find a dull gray coin. You aren't sure if it is made of zinc or steel. 1. You hold a magnet near it, and the coin does not move. 2. Since steel always contains iron, it would have been attracted to the magnet. 3. Because there was no attraction, you can conclude the coin is likely made of a non-magnetic metal like zinc!
Which of these materials would be attracted to a magnet?
What happens to the strength of a magnet's pull as you move an object further away?
True or False: All metals are magnetic.
Review Tomorrow
Tomorrow morning, look at your refrigerator. Can you remember the three special metals that magnets love to pull?
Practice Activity
Go on a 'Magnet Hunt'! Take a refrigerator magnet and test five items in your room. Predict if they are magnetic first, then test them!