• iodine (from a drugstore)
• inexpensive plastic sandwich bag
• cornstarch
• water
• small bowl
• measuring spoons
• eyedropper

1. Place 1 tablespoon of cornstarch in the sandwich bag. Fill it about half full with water. Mix the two and make a knot to tie the bag shut.
2. Mix about 15 drops of iodine with 1 cup of water in a small bowl.
3. Make sure the outside of the sandwich bag is clean and dry before placing it in the bowl. Keep the knot outside of the liquid in the bowl.
4. Wait at least 15 min. Take out the bag and observe.

What did you observe?

some of the cornstarch turned purple
the iodine went clear
the cornstarch leaked out of the bag
nothing happened

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