Can You Eat Metal?

Approximate time to complete: 25-30 minutes + questions and journal time


About This Activity

This experiment is a wonderful extension to combine some of the things you learned from the following topics.

Take a Guess (Hypothesis)

Is there really metal in your food? Can you extract it? (Can you get the metal out?)


First thing first: DO NOT TRY EATING METALS. Many metals are not safe to eat, and even the ones that are can be toxic in high doses.

Note: 300mL = Approximately 1 ¼ Cups

Part 1

  1. Measure out 300mL of General Mills Total Cereal.
  2. Run your magnet over the cereal. Does anything happen?

Part 2

  1. Fill plastic bag #1 with the cereal.
  2. Crush the cereal using the back of a metal spoon. Keep crushing until the pieces are as tiny as you can get them!
Cereal Before Crushing
Cereal After Crushing
  1. Pour the crushed cereal into plastic bag #2 (plastic bag #1 probably has teeny tiny holes in it now).
  2. Pour 300mL of water into plastic bag #2 with the crushed cereal.
  3. Mix the cereal and water, and wait for 5-10 minutes.
Cereal in Water
  1. Hold your magnet on the underside of the bag, and swish the cereal solution around.
  2. Carefully turn the bag over so that the magnet is touching the bag, and the bag under the magnet is touching your cereal solution.
  3. Move your magnet around in circles a few times, then slowly lift the magnet so it hovers just above the bag. What do you see?
Pick up the Magnet
Hold the Magnet Under the Bag
Turn the Bag Over

If you have younger ones, save the bag of cereal solution for a while longer! The cereal will soak up even more water and make for an interesting sensorial experience.

Questions & Further Research

  1. Could you extract magnesium from food with a magnet? (Hint: are all metals magnetic? If you’re a Montessori Laboratory member, you learned about this in your “What Is Magnetic?” experiment).
  2. Can you extract iron with a magnet from any other iron-rich foods like steak or spinach? Why or why not? (Hint: look into how carbohydrates and proteins are digested or broken down).
  3. What are all of the essential minerals that the human body needs? Give an example of where each one can be found.
  4. What is your favorite food? Which essential minerals does it have in it? How much of your daily value of each mineral does your favorite food have? (You can look on the nutrition label, or you may have to look it up on the internet if it is a fresh food like apples).

How It Works

There are metal elements that are found in our bodies, and in our foods. Some examples are magnesium, zinc, and iron. These metals are minerals that our bodies need to function, but that we cannot produce ourselves. They are called essential minerals, and we need to eat them to get them. If you look at the nutrition label on your food, you can see what is in it. Some foods, like certain breakfast cereals, have A LOT of iron in them. The one we used for this experiment has 100% of your daily value of iron.

Total Cereal
Nutrition Facts

When you crush up the breakfast cereal and add it to water, part of the cereal dissolves in the water to make a solution. The iron, however, does not dissolve and floats freely through the water.

We know from experimenting with iron filings and magnets in Combining and Separating that iron will “stick” to magnets. In other words, iron is attracted to magnets.

When you pass a magnet over the cereal solution, the magnet attracts the free-floating iron, and you can see the little pieces of iron that are in your breakfast cereal.


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