UV Beads Lesson Plan Amount of time Demo takes: 5-10 mins.
Try this at home!
Materials
● UV Beads
● String or cordage for making bracelets
● Scissors
● Sunlight or a pocket UV light
● Optional: sunscreen
● Optional: demo bead-lizard
Set-up Instructions
1. Set out bracelet making materials (string,
scissors, etc.) on table. Have a trash bag
or scrap box for extra string clippings.
2. Find a way to neatly manage the beads
(each student will only get five). Put them
in a stable box, for example, to keep them
from spilling.
3. Set out the UV light and demo lizard.
SAFETY!
● Do not let extremely small children play with beads unsupervised!
● Use proper care when entrusting students with scissors.
Lesson’s Big Idea
● Some kinds of light enable us to see colors (red, blue, bright green, etc.). In
this demo, we will use these special beads to show the existence of UV
light, which is normally invisible to our eyes.
Background Information
● We often use the word ‘light’ to mean simply, ‘not dark.’ However, there
are actually many different kinds of light on the electromagnetic spectrum.
There are big, slow radio waves that we cannot see. In the middle are the
wavelengths that are visible to us -- the kinds of waves that show us red,
1/3 blue, and green. Just beyond the visible spectrum is the ultraviolet (UV)
section. UV light is higher-energy and shorter in wavelength than visible
light.
● There are different wavelengths of UV light. The most commonly known
are the long-wave UV lights (“black lights”). These are the kinds of lights
that make rocks fluoresce in the dark, your white t-shirt glow, and some
inks stand out. Short wave UV is the kind used to kill bacteria, etc..
● The beads contain pigments that change colors when exposed to the sun
or other sources of UV light. The dye molecules, when not exposed to UV
light, have two components that are perpendicular (orthogonal, normal, at
right angles) to one another, like two walls intersecting. When the UV light
waves hit the beads with all their energy, they excite the molecules. The
molecules end up forming a bigger entity, which is able to absorb some
wavelengths and bouncing back others for us to see.
Instructional Procedure
1. Invite students to make a bracelet or keychain with up to 5 beads. This is a
demo that they can take home, but is high-cost for us. Do your best to
(politely) ensure that no one is taking more beads.
2/3 2. While they are doing this, talk about the different kinds of light laid out in
the background information section. Discuss UV light and explain to them
why the beads change color in different lights. You can use the demo
keychain during this process.
3. Test the students’ bracelets/keychains with the handheld UV light. Explain
that these will change color outside in the sun -- even on a cloudy day! This
is a good place to remind the students to use sunblock!
Assessment/sample questions you can ask
● What is ultraviolet light, and how is it different from ‘regular’ light?
● Why do these beads change color in UV light?
● What are the dangers of UV light?
● What are some handy, everyday uses of UV lights?
Clean Up
● Neatly package up the beads and strings. Throw away any unusable scraps
and put everything back in the bin tidily. Make note of how many beads
and how much string are left -- let someone know right away if the kit is
running low!
References
● Steve Spangler Science handout (included in bin)
● Arbor Scientific: http://www.arborsci.com/Data_Sheets/P3-6500_DS.pdf
● Knight: Physics for Scientists and Engineers, 3rd Ed. (page 570)
Next Generation Science Standards
● K-5
○ 1-PS4-2
○ 2-PS1-2
○ 4-PS4-2
● 6-8
○ MS-PS1-1/2
○ MS-PS3-1
○ MS-PS4-1/2
● 9-12
○ HS-PS1-1/2
○ HS-PS4-2
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