The Glow-in-the-Dark SparkMeasuring the Luminescence in Glow Sticks

Sarah Maloney

Question

• Do glow sticks glow brighter in warmer temperatures or colder temperatures?

Hypothesis

• If the luminescence of glowsticks is measured at different temperatures,then the glowsticks will display increased luminescence, measured in volts, as the temperature increases

Background Information

• The main chemical in glow sticks in luminol. • Luminol is composed of carbon, hydrogen,

nitrogen, and oxygen• When an atom is excited the electrons go up in

energy and energy levels.  When they fall back down to their normal spot, they release energy in the form of light photons. The more heat applied to the electrons the more sped up they get, so when they fall back down to their normal energy level they release more light.

Materials

• Jar

• Sensor

• Water bath

• Ice bath

• Glow sticks

Procedure

• Assemble Sensor

• Set up water baths

• Set up each glow stick at its designated temperature

• Independent Variable: temperature of water

• Dependent Variable: amount of luminescence (voltage) given off by glow sticks

• Constants: jar, sensor, probe

Data for 40°C Water

40°C 43.6°C 8volts

41.7°C 10volts

42.6°C 10volts

42.4°C 9volts

43.1°C 9volts

Data for 35°C Water

35°C 35.6°C 7volts

35.4°C 5volts

35.5°C 6volts

35.8°C 6volts

35.6°C 5volts

Data for 24°C Water

24°C 25.9°C 4volts

23.1°C 5volts

23.0°C 4volts

24.2°C 4volts

24.6°C 5volts

Data for 15°C Water

15°C 16.7°C 0volts

15.9°C 0volts

16.2°C 0volts

17.1°C 0volts

17.9°C 0volts

Averages

• This graph shows the average voltage for each temperature of water that the glow sticks were placed in. Notice that the voltage of the glow sticks increases as the temperature increases. This suggests that when a glow stick is placed in a hotter temperature, it will glow brighter than when it is

placed in a colder temperature.

0

1

2

3

4

5

6

7

8

9

10

Voltage

40C 35C 24C 15C

Temperature

Average Voltage of Glow Sticks at Different Temps.

Series1

Averages

• This graph shows the average voltage of the glow sticks at different temperatures with error bars. Notice that the error bars do not overlap showing that the results were accurate. This suggests that when the temperature is warmer, the voltage will be higher in the glow stick.

Average Voltage of Glow Sticks at Different Temps.

0

2

4

6

8

10

12

40C 35C 24C 15C

Temperature

Vo

lts

Series1

Trend

• This graph shows a trend that forms from the data of this experiment. The trend line of this graph shows that as the temperature of the water decreases, the voltage of each glow stick increases. This also verifies that the hypothesis was supported.

Voltage at Different Temps.

0

2

4

6

8

10

12

43.6C

41.7C

42.6C

42.4C

43.1C

35.6C

35.6C

35.4C

35.5C

35.8C

35.6C

25.9C

23.1C

23.0C

24.2C

24.6C

Temperature

Vo

ltag

e

Volts

Linear (Volts)

Inconsistencies

• Environment

• Defect in the water bath

http://www.gannon.edu/resource/dept/sim/new/biologyequip.ihtml

Conclusion

• Question- Do glow sticks glow brighter at higher temperature or lower temperature?

• Answer- Glow sticks glow brighter at a higher temperature.

• The hypothesis was supported

References• Casciato, C. (2010, July 16). Ten things to know if you’re going to Global

Dance Festival. Retrieved January 14, 2011, from http://blogs.westword.com/ backbeat/ 2010/ 07/ ten_things_to_know_if_youre_going_to_global_dance_festival_denver.php

• Chaplin, E. (2009, December 1). What Chemicals are in glow sticks? Retrieved October 6, 2010, from Demand Media Property website: http://www.ehow.com/ about_5241805_chemicals-glow-sticks_.html

• The chemical reaction. (1998-2010). How luminol Works. Retrieved October 7, 2010, from Discovery Company website: http://science.howstuffworks.com/ luminol2.htm

• Chemiluminescence . (n.d.). Retrieved 2010, from JRank website: http://www.chemistryexplained.com/ Ce-Co/ Chemiluminescence.html

• Leland, J. K., Nacamulli, L., & Yang, H. (2002). Chemiluminescence. In McGraw Hill Encyclopedia of Science and Technology (Vol. 4, pp. 52-54). McGraw-Hill.

• What does luminol do? (1998-2010). How luminol Works. Retrieved October 7, 2010, from http://science.howstuffworks.com/ luminol1.htm