This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too!


Discover how to detect magnetic fields, learn about the Earth’s 8 magnetic poles, and uncover the mysterious link between electricity and magnetism that marks one of the biggest discoveries of all science…ever.


Materials:


  • Box of paperclips
  • Two magnets (make sure one of them ceramic because we’re going to break it)
  • Compass
  • Hammer
  • Nail
  • Sandpaper or nail file
  • D cell battery
  • Rubber band
  • Magnet Wire

Optional Materials if you want to make the Magnetic Rocket Ball Launcher:Four ½” (12mm) neodymium magnets


  • Nine ½” (12 mm) ball bearings
  • Toilet paper tube or paper towel tube
  • Ruler with groove down the middle
  • Eight strong rubber bands
  • Scissors

[am4show have=’p8;p9;p11;p38;p92;p97;’ guest_error=’Guest error message’ user_error=’User error message’ ]

 


Key Concepts

While the kids are playing with the experiments see if you can get them to notice these important ideas. When they can explain these concepts back to you (in their own words or with demonstrations), you’ll know that they’ve mastered the lesson.


Magnets


  • Magnetic fields are created by electrons moving in the same direction. Electrons can have a “left” or “right” spin. If an atom has more electrons spinning in one direction than in the other, that atom has a magnetic field.
  • If an object is filled with atoms that have an abundance of electrons spinning in the same direction, and if those atoms are lined up in the same direction, that object will have a magnetic force.
  • A field is an area around an electrical, magnetic or gravitational source that will create a force on another electrical, magnetic or gravitational source that comes within the reach of the field.
  • In fields, the closer something gets to the source of the field, the stronger the force of the field gets. This is called the inverse square law.
  • A magnetic field must come from a north pole of a magnet and go to a south pole of a magnet (or atoms that have turned to the magnetic field.)
  • All magnets have two poles. Magnets are called dipolar which means they have two poles. The two poles of a magnet are called north and south poles. The magnetic field comes from a north pole and goes to a south pole. Opposite poles will attract one another. Like poles will repel one another.
  • Iron and a few other types of atoms will turn to align themselves with the magnetic field. Over time iron atoms will align themselves with the force of the magnetic field.
  • The Earth has a huge magnetic field. The Earth has a weak magnetic force. The magnetic field comes from the moving electrons in the currents of the Earth’s molten core. The Earth has a north and a south magnetic pole which is different from the geographic north and south pole.
  • Compasses turn with the force of the magnetic field.

Electromagnetism


  • Electricity is moving electrons. Magnetism is caused by moving electrons. Electricity causes magnetism.
  • Magnetic fields can cause electricity.

What’s Going On?

The scientific principles we’re going to cover were first discovered by a host of scientists in the 19th century, each working on the ideas from each other, most prominently James Maxwell. This is one of the most exciting areas of science, because it includes one of the most important scientific discoveries of all time: how electricity and magnetism are connected. Before this discovery, people thought of electricity and magnetism as two separate things.  When scientists realized that not only were they linked together, but that one causes the other, that’s when the field of physics really took off.


Questions

When you’ve worked through most of the experiments ask your kids these questions and see how they do:


  1. How many poles do magnets have, and what are they?
  2. What happens when you bring two like poles together?
  3. How do I know which pole is which on a magnet?
  4. Is the magnetic force stronger or weaker the closer a magnet gets to another magnet?
  5. What kinds of materials are magnets made from?
  6. Name three objects that stick to a magnet.
  7. Name three that don’t stick to a magnet.
  8. What does a compass detect? How do you know when it’s detected it?

Answers:


  1. How many poles do magnets have, and what are they? Two. North and South poles.
  2. What happens when you bring two like poles together? They repel each other.
  3. How do I know which pole is which on a magnet? Put two magnets together and find the spot where they are repelling the strongest. The poles facing each other are the same. Or bring it close to a compass. If the magnet attracts the needle to north, then the magnet’s pole is the south pole.
  4. Is the magnetic force stronger or weaker the closer a magnet gets to another magnet? Stronger.
  5. What kinds of materials are magnets made from? Iron, nickel and cobalt.
  6. Name three objects that stick to a magnet. Paperclips, pipe cleaners, and staples.
  7. Name three that don’t stick to a magnet. US quarter, glass, plastic.
  8. What does a compass detect? How do you know when it’s detected it? The direction of a magnetic field. When the needle is deflected, the compass is in a magnetic field.

[/am4show]


Have a question ?

Tell us what you're thinking...

Comments

5 Responses to “Special Science Teleclass: Renewable & Alternative Energy”

  1. The phenomenon described in the experiment has also been explained as the Cheerios effect and is attributed to behavior due to surface tension (not magnetism). I’m thinking that the attraction of the cereal is a combination of magnetism and surface tension. So, here is my two part answer. I hope this is accurate:

    1) Since the north and south poles are on opposite sides of magnets, they are happiest connecting end to end. This provides a very slight force that encourages the pieces to form a straight line, which presses the lineup against the curve of the bowl.

    2) The attraction of molecules in liquid causes a membrane on the surface of the liquid. This is part of the phenomenon called surface tension. (That’s how water strider bugs can walk on water) This causes the cereal pieces to make a slight “dip” on the liquid’s surface. Surface tension also causes the liquid to slightly curve up or down along the edge of the bowl. The combination of these two concepts causes the pieces to appear to be attracted to the edge of the bowl.

  2. curlychemist says:

    my mom helps me in since because she used to be a chemist your since is awesome!

  3. curlychemist says:

    We did the cereal magnet experiment. We were wondering why the cereal gravitates to the rims of the palate and not the meddle? C= 1 2 3 4 5 6 7 8 9 10

  4. Awww – so glad you are enjoying the content!

  5. THIS IS SOOOO MUCH COOLER THAN WHAT WE USE TO Do At SCHOOL!!!!!!!