Directions
- Show the students the UV beads and ask them for any observations they can make about the beads.
- Place a small handful of beads on the table and turn on the UV light. Hold the UV light over the beads for a few seconds. Ask the students what changed about the beads. Ask the students what they think caused this change. (You might want to shine an ordinary flashlight on the beads if the students think that light made them change color).
- Have the students take the beads outside in the Sun, if possible. Ask the students why they think the beads change color in the Sun.
- Tell the students that the black light and the sunlight both contain ultraviolet light. Our eyes cannot see ultraviolet light, but the beads will change color in the presence of ultraviolet light.
- Give each pair of students a few beads. Have the students put the beads in a pocket or other dark place and take the beads outside. Have the students face away from the Sun and take out the beads. Make sure they keep the beads in their shadow. Ask the students why the beads changed colors even though they were in the shadows.
- Tell the students that ultraviolet light is scattered by Earth’s atmosphere. UV light from the Sun bounces off molecules in our atmosphere. Some of this UV light ends up bouncing into areas that are in shadow. Therefore, the beads will change colors even if they are in shadow!
- Put some UV beads in the pill bottle. Expose the pill bottle to the Sun or the UV lamp. Ask the students what they notice about the beads.
- Tell the students that pill bottles are designed to block UV light while letting through visible light. UV light can damage drugs so it is important to block UV light.
- Divide the students into small groups. Give each group of students a sheet of acetate. Have the students spread sun block on top of the sheet. Place some UV beads on the table and place the acetate sheet over the beads. Shine the UV light on the beads. Have the students observe if the beads change color.
- Ask the students if they think the sunblock would help prevent sunburn and why.