DETERMINING WHICH COLOR UV BEAD CHANGES COLORS THE FASTEST

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1 DETERMINING WHICH COLOR UV BEAD CHANGES COLORS THE FASTEST Helen C Cary Academy ABSTRACT The purpose of this experiment was to determine which color UV bead changes colors the fastest. The bead colors blue, purple, yellow, orange, green, and red were tested. It was hypothesized that the blue bead would change colors the fastest because the darker the color is, the more light it absorbs. The process followed to perform this experiment was first to take one specific color UV bead and shining the UV light over the bead. Next, the stopwatch was started when the UV light was turned on and when the UV bead stopped getting any bolder, the stopwatch was stopped. The data as recoded and there were 2 more trials for every color and this process was repeated for each color. The averages of the three trials were recorded for each color. At the end of the experiment, the purple bead ended up changing colors the fastest. Its 3 trials were 15.15, 16.58, and seconds. The blue bead s 3 trials were 27.88, 29.15, and seconds. The yellow bead s 3 trials were 30.95, 23.01, and seconds and the orange bead s 3 trials were 42.35, 44.27, and seconds. Lastly, the green bead s 3 trials were 36.90, 35.20, and seconds and the red bead s 3 trials were38.79, 37.10, and seconds. The purple bead was first, the yellow bead was second, the blue bead was third, the green bead was fourth, the red bead was fifth, and the orange bead was last. INTRODUCTION The purpose of this experiment was to find out if color affects how fast a UV bead changes colors. The different colors of UV beads that were tested are yellow, orange, purple, blue, red, and green. The orange bead weighed the lightest at 0.21 grams. The purple bead weighed the next lightest at 0.22 grams. The blue, yellow and red beads weighed the second heaviest at 0.23 grams and

2 finally, the green bead weighed the most at 0.2 grams. The hole on every single bead had a diameter of 0.5 cm and all beads had a diameter of 0.8 cm. On all colors on beads, they were smooth, cold, and mainly white. The beads also had a light tint of color which was the pastel version of the color the beads natural color. The actual UV light source was quite heavy weighing at 645 grams. It had a black cover and the light bulb in it was solid black. When the UV light was turned on, it was a dark violet. The UV light rays were invisible and made the object getting shined on indigo. When bare skin is placed under the UV light, the skin reacted to the light and started warming up. Light is just a type of energy that travels through waves. These waves are different than sound waves or water waves found at the beach. A special type of light that is produced by certain sources of light is called UV light or ultraviolet light. This is an example of light produced by electromagnetic waves which are produced by the sun. This UV light has enough power to hurt or help a person. When too much UV light is absorbed, it can cause sunburns which can eventually lead to skin cancer, wrinkles, and a lot of pain. On the other hand, UV light is so strong, that it can even kill bacteria on foods and sometimes even surgical tools. Also, when exposed to UV light, skin cells produce lots of vitamin D. This specific vitamin allows intestines to absorb calcium which is then used to help make bones and teeth grow to be very strong. The way a UV bead works is because it has a UV active pigment which absorbs UV light. The bead is not actually white although it looks white. When exposed to sunlight or UV light, they reveal their true colors. UV light is invisible to the naked eye which is why the UV rays are not seen. Each bead will change color about 50,000 times before the pigment will no longer respond to UV light. When bare skin is exposed to sunlight, the skin will either burn or tan. UV radiation wavelengths are short enough to break chemical bonds in someone s skin tissue and with over prolonged exposure, the skin may wrinkle or skin cancer may appear. These responses by a person s skin are a signal that the cells under the skin are being assaulted by UV radiation. There are 3 types of ultraviolet light. There is UVA which can cause premature aging of the skin and skin cancer. Tanning beds are an example of a strong source of UVA radiation. The second type of ultraviolet light is UVB which can mainly affect the epidermis. This radiation can cause

3 sunburns, premature aging of the skin and at higher levels, skin cancer. The final type of ultraviolet light is the strongest and definitely most dangerous. It is known as UVC. Fortunately, these rays are stopped by the Earth s atmosphere and do not reach the Earth s surface. When an object appears a certain color when illuminated by white light it means that it is reflecting light of that color and absorbing all other colors. For example, a red apple is reflecting red light and absorbing all other colors of light. The more light the object absorbs, the more heat absorbed since light is energy. If it is considered as a color, black absorbs the most heat. A black object absorbs all wavelengths of light and reflects none. Objects that are white, on the other hand, reflect all wavelengths of light and therefore absorb the least heat. It was hypothesized that the blue bead will change colors the fastest because darker colors absorb more light. The blue bead is the darkest color when light is exposed and when light is not exposed. MATERIALS AND METHOD Different color UV beads (blue, orange, red, yellow, green, and purple) Stopwatch UV light source Flat and open surface First, a color UV bead was chosen out of the container. Next, the UV light was above the bead. When the UV light was turned on and shined over the bead, the stopwatch was started. When the bead stopped changing any darker, the stopwatch was stopped. The data was recorded and this process was repeated 2 more times. The averages were calculated and this process was repeated for each color. The control of this experiment was the bead when not exposed to UV light, the independent variable was the color of the bead and the dependent variable was which color bead changed the fastest when exposed to UV light. The three controlled variables were the same brand of beads, same temperature of the room, and same UV light source.

4 Average Time (s) RESULTS AND DISCUSSION The purple bead ended up changing colors the fastest with an average of seconds. The yellow bead came in second place with an average of seconds and the blue bead came in third with an average of seconds. Green was the next fastest with an average of seconds, and the red bead came in second to last with an average of seconds. Lastly, the orange bead came in last place with an average of seconds. When the experiment was being performed, it was observed that the top of the bead seemed to change faster than the bottom of the bead. The top would be a solid color after 10 seconds but the bottom after 10 seconds but the bottom gradually changed color and took around 30 seconds. The area around the bead also seemed to react to the light by getting warmer Blue Red Orange Yellow Green Purple Color Of UV Bead Figure 1: Average Time of Color Changes for each Bead The purple bead ended up changing colors the fastest with an average of seconds. The yellow bead came in second place with an average of seconds and the blue bead came in third with an average of seconds. Green was the next fastest with an average of seconds, and the red bead came in second to last with an average of seconds. Lastly, the orange bead came in last place with an average of seconds.

5 When the experiment was being performed, it was observed that the top of the bead seemed to change faster than the bottom of the bead. The top would be a solid color after 10 seconds but the bottom after 10 seconds but the bottom gradually changed color and took around 30 seconds. The area around the bead also seemed to react to the light by getting warmer. CONCLUSIONS The hypothesis was not confirmed to be right. It turns out that the purple changed colors the fastest with an average time of seconds where the blue bead s average was seconds. It was inferred that this happened because once the beads were exposed to UV light, the purple bead was the darkest in color and the darker the color is, the faster that color absorbs light. There are a couple ways that this experiment could have been improved. When the UV light was placed above the UV bead, there should have been a specific height that the UV light should have been placed at. Also, when the UV light was turned on, the stopwatch wasn t started at the same time so if this experiment was performed again, there should be one person starting the stopwatch and one person turning on the UV light. These 2 improvements would help make the experiment s data a little more accurate. There are a few other experiments that could be done in this same field of study. The first experiment would include making the beads different temperatures and seeing if this would affect the time it took for the UV bead to change colors when exposed to UV rays. The second experiment that could be performed in this same field would be dipping the UV beads in different liquids and determining if the UV rays would penetrate through the liquid. The third experiment that could be done in this field would be testing the strength of certain brands of sunscreen by seeing which one blocks the UV rays from the UV bead which also means that the bead would stay white. REFERENCES Holt Science and Technology. Sound and Light. Austin: Holt, Rinehart and Winston, Print.

6 Leeds, Grenville, and Lenard's District Health Unit. "Sun Safety- Understanding UV Radiation and the UV Index". Leeds, Grenville and Lenard's District Health Unit. Leeds, Grenville, and Lenard's District Health Unit Web. 22 January Steve Spangler Science. "Color Changing UV Beads". Steve Spangler Science. Steve Spangler Science Web. 22 January 2014.