Magnets only affect certain metals, like iron and steel, and therefore won’t work on materials such as plastic or glass. Most refrigerator doors are made from steel sheet metal, which is what makes them excellent candidates for decorative magnets! Other metals that are not magnetic (copper, gold, or silver, to name a few) can still magnetize slightly when placed in a magnetic field.
Magnetic fields are created by the movement of electrically charged particles, such as electrons. This movement of electrons can be a permanent quality that comes from the material the magnet is made from, like a refrigerator magnet. An example of a non-permanent magnet is an electromagnet. Electromagnets can be produced by an electric current flowing through a coiled wire. Once the electric current that creates a movement of electrons is removed, an electromagnet is no longer magnetic. To learn more about electromagnets, check out a previous blog post here!
Every magnet has a north pole and a south pole. If the same poles of two different magnets are brought near each other, they will repel (push away from each other). But if the opposite poles are placed nearby, they will attract each other! In the picture on the left, someone has placed the same pole of two magnets near each other, and is feeling the repulsion coming from both magnets.
A majority of the planets in our solar system have a significant magnetic field, including Earth! Using probes, scientists have found that Mars and Venus do not have magnetic fields, and while Jupiter has the largest magnetic field, we know that Saturn, Uranus, and Neptune’s fields are all much stronger than Earth’s.
The core of our planet is believed to be an alloy (or mixture) of iron and nickel, which is what gives off its own magnetic force. The most notable uses of this magnetic field are by compasses and birds
Observe Magnetic Fields
- Petri dish
- Iron fillings
- Small magnet
Step 1: Fill your petri dish with a small amount of iron filings. You can find a container of these filings for under $10 at a home improvement store, or by ordering online!
Step 2: Close the petri dish and tape it shut so you don’t accidentally spill the filings. Electric tape works well for this.
Step 3: Observe the magnetic field by holding your magnet against the petri dish. What happens to the iron filings when you bring the magnet closer? Try moving it around the dish and watch carefully!
A, Marc. “Magnetic Dartboard”. Released into the public domain. Uploaded on 5/2/18 from publicdomainpictures.net
Kuiper, Pieter. “Feeling Magnetic Repulsion”. Released into the public domain. Uploaded on 5/2/18 from commons.wikimedia.org
Hodan, George. “Compass”. Released into the public domain. Uploaded on 5/2/18 from publicdomainpictures.net
Hodan, George. “Flying Bird”. Released into the public domain. Uploaded on 5/2/18 from publicdomainpictures.net
Black, Newton Henry. “Magnet”. Released into the public domain. Uploaded on 5/3/18 from commons.wikimedia.org
Magnet and materials images property of Discovery Express Kids, LLC.