Testing Glowsticks

by: Madelon Cheatham

Overview

During this hands-on activity, students will learn about heat and temperature by experimenting with a Glow stick. This activity demonstrates concepts related to heat exchange and employs measurement with scientific tools.

Introduction

Background Information

In this lesson, participants will become familiar with using and recording information taken with a thermometer. They will also learn about the relationship between heat and energy.

Molecules with a lot of energy move faster than molecules with a smaller amount of energy. In this activity, participants will use heat as an energy source to illustrate this phenomenon. When a Glowstick is placed in hot water, the molecules inside the Glowstick move faster, causing it to shine brightly. When the Glowstick is placed in ice water, the molecules inside the Glowstick move slower. This results in less illumination.

Getting the Lesson Started!

Here are some potential discussion questions:

  1. What provides energy for molecules to move?
  2. Do molecules move faster when it is hot or cold?
  3. How can we measure temperature?
  4. How can we design an experiment to see if molecules move faster in hot water?

Materials

  • one Glowstick (per group of students)
  • two Styrofoam cups
  • one thermometer
  • 1/2 cup ice
  • hot and cold water

Materials Pictured Below:

Instructions

  1. Remove a Glowstick from its wrapper. Bend the Glowstick until you hear a snap. This will activate the Glowstick.
  2. Place hot water in one Styrofoam cup and ice water in another Styrofoam cup.
  3. Start with the cup containing the hot water. Test the temperature of the water by placing the thermometer in the water. Record the temperature. Next, place the Glowstick in the hot water. Record an observation.
  1. Now test the cup containing the ice water. Place the thermometer and the Glowstick in the water. Record the temperature and an observation about the Glowstick.

Math can be integrated into the lesson by having the students calculate the difference between the temperature of the hot water and the ice water. They may want to vary the temperatures and monitor the results. From this, students may make further connections between heat and molecular movement.

Testing the Effect of Heat on Temperature- Activity Questions

Predictions

  1. What do you think the Glowstick will look like in the hot water?
  1. What do you think the Glowstick will look like in the ice water?
  1. What should the temperature of the ice water be?

Data Collection

Cup / Temperature (F) / Glowstick Observation
Hot Water
Ice Water

Explanation

______

______

______

______

Summary

  1. How did your Glowstick observations differ? What do you think caused this difference?
  2. What was the temperature of the cold water? Was this what you expected?

Assessment

Assessment Background

During the Lesson

The students use inquiry strategies to analyze the results of their Glowstick observations. Through their analysis, they were able to make a connection between molecules and heat, the energy source. Throughout the lesson, the students discuss their understanding and teachers may use this as an assessment of their acquisition of new knowledge. .

At the End of the Lesson

At the conclusion of the lesson, discuss the student’s understanding of how heat affects molecules. Also encourage them to think critically about how heat can be used in society.

Sample questions to discuss. :

  • What is heat used for in your home or at school?
  • What types of energy sources are around us?
  • What is the relationship between heat and molecular movement?
  • How can heat be measured?

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