Safety note: Be sure to explain safety precautions to children. This experiment uses hot water. Skin protection should be used. Avoid getting chemicals from the the inside of the glow stick on skin, eyes, or clothing. After these experiments dispose of glow sticks in garbage. Disclaimer: All information provided on this site is for entertainment and education purposes only. Using any information from thecasabouquet.com is at your own risk.
- Give the children two cups and 2 or 3 glow sticks of the same color. You may want to use coffee cups to help with insulation. If you have several teams of students, try giving each team a different color glow sticks to work with for comparison.
- Ask the children to make observations of the glow stick and sketch the inside of the stick.
- Distribute water and ice cubes and water that is close to boiling. Record the temperature of each cup.
- Bend the glow sticks (to break the ampule inside) and make observations. Put one stick in the hot water and one in the cold (if you have a 3rd stick, leave it on the table for room temperature). Observe and record the color and amount of light.
- Turn off the lights and observe. You may also want to try a black light for more observations.
What questions can you answer with an experiment like this? Do different color glow sticks behave differently with temperature changes? Can you detect a difference in brightness between different temperatures of water, between 0oC and 100oC? What happens if you switch the sticks from the two cups? How long will a glow stick give off light in the freezer, or room temperature, or in hot water? Can you think of more?
- Safety glasses,
- 2 cups,
- 2 or 3 glow sticks,
- very hot water,
- water with ice,
- paper towels,
- paper or notebook for recording results, pen
A tip for teachers: I did not have hot tap water or a microwave available in my classroom. I tried to use the old immersion heating coil that is relatively inexpensive. I found it dangerously hot to use around children and it shorts out easily. My favorite was a plug in teakettle. It costs a bit more, but is safer, long lasting, and portable.
What is the science?
Content: thermal energy, chemical reaction, fluorescence
Light sticks are examples of luminescence and fluorescence. The chemical reaction that starts when you break the glass ampule in the lightstick releases enough energy to cause the electrons in the fluorescent dye to get excited. Immediately these electrons drop back down to their normal state and give off energy in the form of light. In this experiment you are using the thermal energy of the hot and cold water to change how quickly the reaction happens.
- Science of Energy from need.org has a whole set of energy lab activities and worksheets
- Fun things to do with glow sticks from Hub Pages
- 25+ Glow in the dark hacks and must-haves from Kids Activities Blog
- Safety information on glow sticks from Steve Spangler Science
- The chemistry of glow sticks from Compound Interest
- How do lightsticks work? From About Education
- Temperature sensors from Vernier Software & Technology
I’ve found that children love wearing glow sticks on a necklace or the thin bracelet kind. This experiment has a good excitement value. So make a point to stock up on glow sticks when they are abundant and colorful, such as at Halloween and July 4th!
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