What is needed

• Iron-fortified cereal (look on the label for a cereal that lists "iron" or "reduced iron" in the ingredients; one that provides 100% of your daily requirement is best.)
• Blender
• Strong magnet

What to Do

The folks at the cereal company put the iron in the cereal; now we are going to take it out! Here's what you need to do:

 

• Take some cereal, and put it in a blender with some water. (You can use milk if you like, but it is pretty messy!) Blend it for a while, and then let it sit for at least five minutes.

  

  • Here is David Sites doing the first stage of this experiment on the "Everyday Science" television program.
• Next, pour the gooey cereal mixture into a glass, plastic or cereamic bowl - don't use a metal bowl! Now, take a really strong magnet, and fish it around in the bowl. Do this for a while; don't be squeamish. You will find that some iron sticks to the magnet - this is the iron from the cereal! (Note: you need a really strong magnet to do this. Normal refrigerator magnets won't work. If you would like to know where you can get really strong magnets, you can e-mail the Little Shop of Physics and we will give you some ideas.) Note: it will be pretty hard to get the filings off the magnet, but we have found that duct tape does the job.

What is Happening

It turns out that when the folks who make your breakfast cereal add iron to it - which is good for your health - they actually add iron! Little bits of iron - iron filings - can be found in the cereal. This is OK, as the filing will be rapidly broken down in your stomach. But you can use a strong magnet to pull out the filings. This is a nice example of a mixture: the cereal is mixed with the iron filings, but they are not chemically combined at all.

Other Things to Try

You can find iron filings other places too; in Fort Collins, there is a lot of iron in our sand, for instance. Take a magnet to the playground, and swoosh it around in the sand - you are certain to pick up a bunch of iron along the way!