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Disappearing Crystals

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    American Physical Society

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Disappearing Crystals

Learners experiment with water gel crystals, or sodium polyacrylate crystals, which absorb hundreds of times their weight in water. When in pure water, the water gel crystals cannot be seen. However, when learners place the crystals in solutions of Splenda and water, the crystals can be seen. Learners use this property to determine how much Splenda is in 4 different cups of water. This is one of four activities learners can complete related to PhysicsQuest 2008. Each activity gives a clue to solve a puzzle in the accompanying comic book, "Nikola Tesla and the Electric Fair."

Quick Guide

Preparation Time:
4 to 24 hours

Learning Time:
45 to 60 minutes

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

Age Range:
Ages 11 - 18

Resource Types:
Activity, Experiment/Lab Activity


Materials List (per group of students)


  • Mathematics
    • Measurement
      • Units of Measurement
  • Physical Sciences
    • Chemistry
      • Solutions
    • Light and Optics
      • Reflection and Refraction
    • States of Matter
      • Liquids
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations

Informal Categories

  • Literature


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


Components that are part of this resource:

This resource is part of:

Access Rights:

  • Free access


  • American Physical Society


  • All Rights Reserved, American Physical Society, ©2009


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