Iodine Investigators!

Source Institutions

Source Institutions

Add to list Go to activity
Activity link broken? See if it's at the internet archive
In this activity on page 7 of the PDF (Chemistry—It’s Elemental), learners use iodine to identify foods that contain starch. Compare the starch content of a ripe banana, an overripe banana, milk, and flour mixed with water. Use this experiment to introduce learners to starch and how our bodies use starch to break down nutrients during digestion.
Safety notes: DO NOT eat any tested foods or the iodine. Wear goggles. Follow the safety tips on the bottom of page 7 as well as Milli's safety tips on page 5.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
10 to 30 minutes

Estimated Materials Cost:
$1 - $5 per student

Age Range:
Ages 6 - 14

Resource Types:
Activity, Experiment/Lab Activity

English, Spanish

Materials List (per student)

  • dropper
  • iodine
  • 1 tablespoon of flour mixed with 1/3 cup of water
  • 1/3 cup of milk, for comparison
  • starchy foods to test: banana slices that are overripe (turning brown) and unripe (green)
  • 2 plastic cups or containers
  • measuring spoons
  • 2 paper plates
  • paper towels


  • Life Sciences
    • Diversity of Life
      • Plants
    • Human Body
      • Digestion
      • Health and Nutrition
  • Physical Sciences
    • Chemistry
      • Chemical Bonding
      • Chemical Reactions
      • Acids and Bases
      • Chemistry of Life
      • Solutions
    • Structure and Properties of Matter
      • Atomic Structure
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations
      • Communicating Results

Informal Categories

  • Food and Cooking
  • Nature and Environment


To use this activity, learners need to:

  • see
  • see color
  • read
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


Foreign language versions of this resource:

Access Rights:

  • Free access


  • Office of Community Activities, American Chemical Society


  • All rights reserved, American Chemical Society, 2009