|Sam (age 10) tests an apple slice, which stays brown, and a mini marshmallow, which turns black. |
|Sam (age 10) tested several food items. Most of the results turned out as he expected, but he was surprised that peanut butter tested positive for the presence of starch. |
For upper-level students, you can tell them that iodine specifically detects polysaccharides and will not pick up mono or discaccharides.