Introduction

Be prepared for a colorful change thanks to the Sun’s ultraviolet waves.

Objectives

To see that the Sun emits ultraviolet rays

Materials

•  UV detecting beads
•  Sunny day
•  Pipe cleaner (optional)

*UV beads can be purchased at most teacher supply stores or online at science supply sites. **For an extended activity, try putting different SPF levels of sun­screen on the beads to demonstrate how sunscreens will block the UV rays, modeling how it protects our skin.

Procedure

On a sunny day, provide each child with some UV beads. The UV beads will remain white as long as they are indoors. Keep them away from any sunlight. They are very sensitive! Have the children hold them tightly in their hands and tell them not to peek at their beads until the designated time. Next, take the children outside with their UV beads. Count to three and have them open their hands. What happens when the beads are exposed to sunlight? If the children are allowed to keep their beads, they might want to string them on a pipe cleaner. They can then “wow” their friends and family

Conclusion

The beads have a pigment in them that will change colors when exposed to the UV radiation from the Sun or a UV light. Our atmosphere’s stratospheric ozone layers protect us from most of the UV radiation. However, some of the UV rays escape the ozone layer and can have damaging effects. The changing beads prove that UV rays are hitting Earth. It is the ultraviolet rays that cause sunburn and eye damage. Sunscreen and sunglasses can help absorb the UV photons (small particles of light too small to see individually).