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Whelmer #7: Iron in Cereal

Illustration of a magnet taped to the end of a glass rod. The magnet has attracted iron particles to it.
Description:
A small magnet is used to remove particles of iron from common breakfast cereal.

Science process skills:
observation, classification, and measuring

Complex reasoning strategies:
comparison, classification, and induction

Standards:
K-4
  • Employ simple equipment and tools to gather data and extend the senses. (A.1.3)
  • Magnets attract and repel each other and certain kinds of other materials. (B.3.4)
  • Nutrition is essential to health. Students should understand how the body uses food and how various foods contribute to health. Recommendations for good nutrition include eating a variety of foods, eating less sugar and eating less fat. (F.1.3)
5-8
  • A substance has characteristic properties. (B.1.1)
  • Chemical elements do not break down during normal laboratory reactions. (B.1.3)
  • Cells carry on the many functions needed to sustain life. This requires that they take in nutrients, which they use to provide energy for the work that cells do and to make the materials that a cell or an organism needs. (C.1.3)
9-12
  • Most cell functions involve chemical reactions. Food molecules taken into cells react to provide the chemical constituents needed to synthesize other molecules. (C.1.2)
  • Selection of foods and eating patterns determine nutritional balance. (F.1.5)
From the National Science Education Standards

Content topics:
food digestion, human physiology, and nutrition

You will need:
  • Total® brand cereal, or other high iron content breakfast cereal
  • mixing bowl
  • plastic or glass rod
  • large spoon
  • magnets
  • zip type bags (optional)
Instructions:
Place the entire contents of a box of flakes into a large bowl. Use your hands to crush the flakes to pin-head size pieces. Add water and stir. Use additional water to keep the mixture thin and soupy. Tape a small magnet on the end of the glass rod. Stir the cereal soup with the magnet for several minutes. Small bits of pure iron will collect on the magnet!

A variation of this activity is to mix the cereal and water in a sealed zip type bag. A large magnet is pressed to the outer surface of the bag. Particles of iron will collect inside the bag, near the magnet.

Presentation:
At the beginning of the activity, present a large nail or spike and ask students if they would like to eat some of it. You can also use a metal file to scrape off small pieces to make the iron more palatable for the students!

Mix the box of crushed flakes with water. Stir for 15-20 minutes. The particles of iron are very tiny and the mixing process dislodges them from the flakes. Following the description on the side of the cereal box, direct the students to collect the amount of iron indicated in the "recommended daily allowance" column. If you do not have a milligram balance, student can make a rough determination by an indirect method. Allow them to develop their own plan.

Wash the iron collected and dry it on absorbent paper. Use the cereal box to determine the number of servings included in the box. Divide the iron into that many equal piles.

Content:
The human body requires iron for many functions. Most importantly, iron is used in the production of hemoglobin molecules in red blood cells. It is the iron in the hemoglobin that attracts oxygen molecules, allowing the blood cells to carry oxygen to body cells. Red blood cells are constantly being replaced. Therefore, there is a constant need for a new supply of iron in the diet. That is why iron is often mentioned as a healthful additive to certain foods and vitamin pills.

The iron in the cereal is pure iron! Really! It is the same iron found in nails and automobiles. It is mixed in the cereal batter along with many other additives. The very tiny particles of iron quickly react with hydrochloric acid and other chemicals in the digestive tract, changing to a form easily absorbed by the body.

Assessment:
Type: groups of two or three
Content/Process: nutrition
Age/Level: Intermediate and higher

Have cereals containing various amounts of iron available for use. Follow the procedure in Whelmers #7 using two different types of cereal. Compare the amounts of iron claimed to be present in one serving of each cereal. Based on your findings, determine the validity of the claims of the cereal manufacturers. Record the group results on the board. Students' conclusions should correspond to the amount of iron obtained and the claims of the manufacturers of the cereal.

Notes:






  
     
 

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