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UV Beaded Bracelet

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Physics Volunteer Activities

Create a bracelet with beads that react to UV light.

What You Need

For each child:

  • 1 piece of elastic cord
  • 7 UV beads

Instructions:

Safety Notes

Do not put the beads in your mouth, nose or ears.

What To Do

1. Thread the 7 beads onto the elastic cord.
2. To hold the beads onto the elastic cord so they don't move, take one end of the elastic cord, wrap it around the last bead and put it through hole of the last bead like in the photos below.
3. Fit the bracelet to your wrist and tie a knot to hold it on your wrist. Don't make it too tight.
4. Cut the extra ends of elastic cord off. Wear your bracelet outside in the sun and watch the beads change from white to coloured. If you can't get outside, find a sunny place in your home and put your beads in the sun.

Discovery

What's Happening?

One type of light from the sun is called UV light. There is a chemical in the beads that changes colour when UV light shines on them. The beads stay white if there is no UV light on them.

What's Happening?

One type of light from the sun is called UV light. There is a chemical in the beads that changes colour when UV light shines on them. The beads stay white if there is no UV light on them.

Investigate Further

Do some experimenting
Do your UV beads change colour if you are in the shade? If so, this means some UV light is still getting to the beads and your skin even though you are in the shade. What happens when you go back into your house? Are your UV beads still coloured? If so, wait a bit and see if they change? There isn’t any UV light in your house. If you have sunscreen, you could try putting sunscreen on some of the beads and not others and then put them in the sun and see what happens. Does the sunscreen keep the UV light away from the beads?

Investigate Further

Do some experimenting
Do your UV beads change colour if you are in the shade? If so, this means some UV light is still getting to the beads and your skin even though you are in the shade. What happens when you go back into your house? Are your UV beads still coloured? If so, wait a bit and see if they change? There isn’t any UV light in your house. If you have sunscreen, you could try putting sunscreen on some of the beads and not others and then put them in the sun and see what happens. Does the sunscreen keep the UV light away from the beads?

Resources

Resources