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In this experiment, learners will conduct chemical and physical tests to identify mystery substances. This experiment is very flexible, allowing educators to determine the number of unknowns to analyze and tests to conduct, as well as the depth of inquiry based on the time they have at their disposal. The activity is a simplified version of "qualitative analysis," a technique used by scientists to identify unknown substances using concepts such as conductivity and solubility. Background questions and explanations are included, as is an extension game.

Quick Guide

Preparation Time:
10 to 30 minutes

Learning Time:
45 to 60 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 8 - 14

Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan

English, Spanish

Materials List (per group of students)

  • corn starch, 1 tablespoon
  • granulated sugar, 1 tablespoon
  • baking powder, 1 tablespoon
  • cream of tartar, 1 tablespoon
  • baking soda, 1 tablespoon
  • table salt, 1 tablespoon
  • laundry detergent (must contain sodium carbonate), 1 tablespoon
  • Epsom salts, 1 tablespoon
  • dry milk powder, 1 tablespoon
  • baby powder, 1 tablespoon
  • plaster of Paris, 1 tablespoon
  • Alka-Seltzer tablets, 1 tablespoon
  • ice cube trays (to distribute powders)
  • small plastic cups (for mixing)
  • plastic spoons (for powders)
  • plastic spoon (for mixing)
  • Styrofoam or plastic egg carton, preferably white in color
  • pop-top squeeze bottles (e.g. water or sports drink), 6 oz. or larger
  • vinegar, 1/4 cup
  • tincture of iodine, 2 teaspoons
  • red cabbage, 1/4 cup
  • water, 2 cups
  • toothpicks, 10–12
  • magnifying glasses (optional)
  • paper towels


  • Life Sciences
    • Human Senses and Perception
      • Smell
      • Vision
  • Physical Sciences
    • Heat and Thermodynamics
      • Heat and Temperature
    • Electricity and Magnetism
      • Electric Charges and Currents
    • Chemistry
      • Chemical Reactions
      • Acids and Bases
      • Solutions
    • States of Matter
      • Solids
      • Liquids
      • Gases
      • Changes of Phase
  • The Nature of Science
    • The Scientific Process
      • Asking Questions
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations

Informal Categories

  • Crime Science
  • Food and Cooking


To use this activity, learners need to:

  • see
  • see color
  • read
  • smell
  • touch

Learning styles supported:

  • Involves teamwork and communication skills
  • Involves hands-on or lab activities


Foreign language versions of this resource:

Components that are part of this resource:

Includes alignment to state and/or national standards:

Access Rights:

  • Free access


  • Oregon Museum of Science and Industry


  • All rights reserved, Oregon Museum of Science and Industry, 2007

Funding Sources:

  • National Science Foundation
  • Camille and Henry Dreyfus Foundation