Tuesday, March 9, 2010

Mystery Bracelet



Tonight I got the chance to work with the 4H club here in Virginia Beach. We did some really cool science experiments. Tomorrow I will post some other ideas we played with.

With springtime just around the corner, here is a great experiment to do with your kids while showing them the importance of sunscreen!

Does SPF really matter?

Materials:
  • UV sensitive beads (ordering information listed below)
  • Sunscreen (15 and 30)
Procedure:
  1. Begin by having your child make observations of the bead: so what does it look like? (color: white; texture: smooth; shape: round)Feel like? (hard) record these ideas.
  2. Ask your child, what can you do with this bead? (make a necklace, bracelet, put it in your hair)
  3. Tell your child the bead has special properties. Have them make a bracelet with one or more of the beads. Then go outside (needs to be sunny). Don't say anything until your child notices the bead(s) have done something really cool!! (they change color in the sunlight)
  4. Ask your child to give you all of their questions they have about the bead. If you have the time, allow your child to find the answers to his/her question. For example,do the beads change in regular light? (they don't, but let your child find the answer and record it)
  5. Next, tell your child you have been wondering about the effectiveness of sunscreen-specifically if higher numbers matter. What could we do to find the answer to this question? (hopefully they will tell you to put sunscreen on the bead and then observe to see if it changes color)
  6. Conduct the experiment and see how the bead changes when you put SPF 15 or 30 on them. Have your child do three tests and then take an average.

Other questions your child can test: Does the time of day make a difference with regard to the rate of color change? Does the brand of sunglasses make a difference in terms of how much they change color? Do the beads change color while put under water? What does the bead do under a regular light bulb?

Content Help for Parents: The beads contain a pigment that is sensitive when exposed to UV light from the sun or other UV sources (UV flashlights will work, but the beads will not be as clear). Beads are not affected by visible light, so they do not change color inside and are not affected by light bulbs.

To order the beads:
http://www.teachersource.com/ (you can get one bracelet kit for $5.95; assorted bag of colors about 250-$6.95)
http://www.stevespanglerscience.com/ (for 250 beads-$6.95)
www.brightguy.com (to order a UV flashlight-they run about $32)