Investigating Iron-Fortified Food
Initial Publication Date: August 24, 2007
Summary
After studying that iron is attracted to magnets, students will use magnets to extract food-grade iron filings from iron-fortified food.
CollapseLearning Goals
Students will gain experience with using a magnet as a tool to determine the presence of iron in food.
Students will observe, discuss, and then model a demonstration of finding iron in food.
Students will write about the activity in their Science Journal.
Concepts
Iron is attracted to magnets.
To ensure that we have enough iron in our diets, some foods are fortified with iron.
We need iron so we aren't as tired and may be less likely to get sick.
Vocabulary
Iron-fortified
Cow magnet
Students will observe, discuss, and then model a demonstration of finding iron in food.
Students will write about the activity in their Science Journal.
Concepts
Iron is attracted to magnets.
To ensure that we have enough iron in our diets, some foods are fortified with iron.
We need iron so we aren't as tired and may be less likely to get sick.
Vocabulary
Iron-fortified
Cow magnet
Context for Use
Grades 4—6
Large group demonstration
Small group investigations
Time: 30 minutes
Prior Knowledge: Students should know that iron is attracted to magnets.
Large group demonstration
Small group investigations
Time: 30 minutes
Prior Knowledge: Students should know that iron is attracted to magnets.
Description and Teaching Materials
Materials
Plastic bags
Unsharpened pencil (1/group)
Cow magnets (1/group)
Magnifying lens (1/group)
2 rubber bands / group
1 twist tie / group
White paper
Variety of iron-fortified food (ferric phosphate won't work)
Procedure
1. For each group, attach a magnet to a pencil with the rubber bands. Insert this "stirrer" into a plastic bag and fasten the bag with the twist tie.
2. Show students one of the unopened containers of fortified food to be tested.
3. Discuss what "iron-fortified" might mean. Ask, "Do you think we can see the iron in the food?"
4. Pour about 3 tablespoons of food in a bag for each group. Have them observe the bag carefully. Ask, "Can you see anything that might be iron?" "How can we find out if there is iron in the food?" Through discussion, lead students to conclude that a magnet could be used.
5. Model the following steps:
a. Stir the food in the bag with the "stirrer".
b. Remove the stirrer and use a magnifying lens to observe the iron filings clinging to the bag.
c. Undo the twist tie from the stirrer and remove it from the bag, allowing the iron filings to fall onto a piece of white paper.
d. Place the magnet under the paper and move it around, observing the magnetic behavior of the filings.
6. Have students follow the same steps to check other bags of food.
7. Have each group share what they discovered.
8. Ask, "What is this iron you saw? Do you think this is the same thing used for weights that you lift? (pumping iron) Explain that food actually has food-grade iron filings added to it by the manufacturer. Discuss the nutritional importance of iron.
9. Have students draw and write about the investigation in their Science Journals.
Gertz, Susan, Dwight J. Portman, and Mickey Sarquis. Teaching Physical
Science Through Children's Literature . Terrific Science Press. 1996. 107-113.
Plastic bags
Unsharpened pencil (1/group)
Cow magnets (1/group)
Magnifying lens (1/group)
2 rubber bands / group
1 twist tie / group
White paper
Variety of iron-fortified food (ferric phosphate won't work)
Procedure
1. For each group, attach a magnet to a pencil with the rubber bands. Insert this "stirrer" into a plastic bag and fasten the bag with the twist tie.
2. Show students one of the unopened containers of fortified food to be tested.
3. Discuss what "iron-fortified" might mean. Ask, "Do you think we can see the iron in the food?"
4. Pour about 3 tablespoons of food in a bag for each group. Have them observe the bag carefully. Ask, "Can you see anything that might be iron?" "How can we find out if there is iron in the food?" Through discussion, lead students to conclude that a magnet could be used.
5. Model the following steps:
a. Stir the food in the bag with the "stirrer".
b. Remove the stirrer and use a magnifying lens to observe the iron filings clinging to the bag.
c. Undo the twist tie from the stirrer and remove it from the bag, allowing the iron filings to fall onto a piece of white paper.
d. Place the magnet under the paper and move it around, observing the magnetic behavior of the filings.
6. Have students follow the same steps to check other bags of food.
7. Have each group share what they discovered.
8. Ask, "What is this iron you saw? Do you think this is the same thing used for weights that you lift? (pumping iron) Explain that food actually has food-grade iron filings added to it by the manufacturer. Discuss the nutritional importance of iron.
9. Have students draw and write about the investigation in their Science Journals.
Gertz, Susan, Dwight J. Portman, and Mickey Sarquis. Teaching Physical
Science Through Children's Literature . Terrific Science Press. 1996. 107-113.
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Assessment
Students will hand in their journals to be read and checked for understanding.
Standards
Grade 4, I, B—Scientific Inquiry—controlled scientific investigation
Grade 4, II, E—Forces of Nature—magnetism
Grade 4, II, E—Forces of Nature—magnetism