applications anJ analogies
edited by RONDELORENZO Middle Georgia College Cochran, GAS1014
Candy Sprinkles To Illustrate One Part Per Million Clifton E. Meloan, Mindy L. Meloan: and John M. Meloan' Kansas State University, Manhattan, KS 66506 The concept of one part per million often is hard for some to grasp, particularly nonscientists and beginners in science. The senior author has looked for many years to find a convincing and practical hands-on way that would illustrate one part per million. What was wanted was something that would not weigh too much to be handled, would be rugged enough so as not to break when handled, would be inexpensive so any teacher could use the idea, would provide a challenge to the students, and would be innovative enough so that the student would remember it. The problem was solved by the senior author's grandchildren who were eating cupcakes covered with candy sprinkles. Sprinkles are small, inexpensive, and obviously rugged. What size volume would 1,000,000 sprinkles occupy? When 3,000 sprinkles were counted, they weighed 15.8596 g. Therefore, 1,000,000 would weigh 5,246.53 g. A regular bottle contained 166 g, so 31.8 bottles would be needed. The candy in the bottle occupied 10.8 in3, so 31.8 bottles would require a volume of 34 in3; about 1.5 gallons. This is a reasonable volume. There should be some excess
volume so the students can roll the container to locate the odd particle. An appropriate container was harder to find than expected. The container chosen was a 2.2 gallon mostly clear plastic spherical fish aquarium tank. This has a flat base, so it is less likely to roll off a table top, and being plastic it is less likely to break if dropped. A million candies would require a lot of vacuuming. Multicolored sprinkles are preferred (white, yellow, light orange, pink, red, blue, green, and purple) because it is harder to find the odd one. While there were no black candies in the mixturethere are several dark purple ones that looked black in the right light. These were removed by placing the candy in a tray and picking out 1,738with tweezers. Two black beads were added, one 2 mm in diameter and one 4 mm (faceted)in diameter. .The big bead is for "beginners" and the small bead is for "old pros". These beads are clearly black and have a.hole in the middle so they can be identified readily if they can be located. They are similar, yet different enough that they can be found, and each one is still 1ppm. There are two small cavities in the top of the container and examples of each type of bead to be found were glued into them. A small sign, "Beginners" and "Old Pros" was pasted to the inside of the cavity. A small sign indicating what this was and what was to be done was pasted to the side. The Sian
This globe contains 1,000,000candies Can you find the blackone? Roll it around and look carefully. The large one is for 'Beginners". The small one is for "Old Pros". I
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A cork was glued into the filling port, and the extra was trimmed away. The air port extension from the bottom was cut off and glued shut. The final weight was about 12 pounds. Total cost including two packages of beads and tax was $48.05. See how long it takes you to find the black one. That's one part per million. It's really tough. . Some who have triedsay i t i s impossible. Materials Spice Classics, candy sprinkles; $0.70bottle at Sam's. 166 g label weight, 171 g actual. 2.2 gallon aquarium globe; Great Western Trading Co. 2512 Summit Ave. Suite 304, Plano, TX 75074. $21.95 at WalMart. $21.95. Black Seed beads (8950)and black Facet beads (89931, Fibre-CraR Materials Co. Niles, IL 60648. Obtained at a local craft store. $0.54/pkg.
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Plastic sphere containing 1 million candy sprinkles.
658
Journal of Chemical Education
'currently MLM and JMM are residing in Hewin. Texas.
