UV Bead Bracelet Activity
Objective: The students will create a bracelet made of UV beads and expose it to
UV light outside the classroom. Through this activity, students will gain an
understanding of how the UV beads react when exposed to sunlight for different
time periods and create a 0 – 3 qualitative scale of color.
Materials Needed:
 30 cm. piece of pre-cut hemp cord
 10 UV beads
 Stopwatch
 Colored pencils
 Lab directions
It is important to choose a sunny day to complete this activity
Directions:
1) Break students up into groups of 4. Each group should needs a copy of the
lab directions, a stopwatch, and colored pencils in the color that the UV
beads will change .
2) Each student should get 1 piece of 30 cm. pre-cut hemp cord and 10 UV
beads.
3) Each student should tie a knot in their hemp cord about 10 cm. in from
one end. Thread the 10 beads onto the thread and arrange them so that
they stop at the knot. Tie a second knot at the end of the line of the 10 UV
beads. Have a lab partner tie the bracelet onto one of their wrists so that
the beads are resting on the top of their wrist.
4) One student should be assigned to expose their bracelet for 0 sec. to UV
light, one for 10 sec., the third for 20 sec. and the final student for 30 sec.
5) Once all the students in the group have made their bracelets and have
them on their wrists, the group should proceed outside carrying the
stopwatch, colored pencils, their own writing instrument and the lab
direction sheet with them. One student needs to hold the stopwatch and
Be responsible for timing the 30 second time frame. (It will probably work
best if this is the 30 sec. person)
6) Immediately upon reaching sunlight the timer should turn on the
stopwatch and begin timing. The student assigned to the 0 sec. of UV light
exposure should not allow the beads to be exposed to any sunlight. They
can accomplish this by keeping their other hand tightly over the beads.
7) When 10 seconds have elapsed, the timer should call out “10 sec.” and the
Student who was assigned this time frame should cover the beads with
their other hand. Repeat this step for 20 sec. and 30 sec.
8) At the end of 30 seconds, all students should return to the classroom and
note the color of the UV beads in the following table. In addition to noting
the color, they should use the colored pencil to indicate the shade of the
beads to the best of their ability.
Table 1: Results of UV bead exposure to sunlight at various times
Time (sec)
Color of beads
Shaded drawing of bead
0
Scale =0
10
Scale = 1
20
Scale = 2
30
Scale = 3