Solar Bead Science

As much as I love all  things STEM, the Science Fair has never been my favorite school activity. I think it has something to do with designing that darn science board… Anyways, this year I  FINALLY found a science fair project that was not only relevant to my students’ lives, but also super easy-to-prep and fun for all!

Living in Florida, there is one thing we never have a shortage of- sunshine! And with that comes a definite need for sunscreen. But as a consumer, and for sure as a kid, it’s hard to know which SPF is best, and if those crazy high numbers actually make that big a difference. I mean, I’m not saying that SPF 8 is your best bet for fighting sunburn and skin cancer. But, is SPF 100 really that much better than SPF 30 or SPF 50? That’s exactly what this science experiment is designed to find out.

The Setup

For this experiment, I would recommend buying all the same brand of sunscreen. This isn’t required, but it would minimize any error that may come from different brands’ formulas. {I did not do this in the original experiment and you’ll see the wonky results I got below. My SPF 30 was clearly not working properly.}

Before starting the experiment, I showed my students how the solar beads worked. We started off by talking about what they looked like inside our classroom, and then we took the bag outside to let the “magic” happen. Students were so excited to see how the sun’s rays turned our plain old white beads into vibrant purples, pinks, oranges, and blues! Once the students understood how the solar beads worked, it was time to prep for the actual experiment.

Here’s what I used:

  • Solar Beads (I got mine on Amazon)
  • Banana Boat Sunscreen- SPF 15, 30, and 100
  • 4 paper plates- white works best to compare the color change

The Experiment

We started off by putting 30 (ish…) solar beads on each of the paper plates and then labeling each one with the kind of sunscreen we’d use on it. I sprayed each of the plates with sunscreen pretty thoroughly (about 10 seconds or so) until all beads looked wet. I let them dry for a minute before taking them into the sun, just like you do when you put sunscreen on yourself.

Then, we took our plates out to the playground and placed them in the sun. Ta-Da! Sunshine magic. We then compared the colors of beads on each plate to determine which SPF was the most effective at protecting our beads from the sun’s rays.

What was really interesting was that the SPF 30 actually did WORSE than the SPF 15! You can see above that my SPF 30 looks frightningly similar to NO sunscreen. I have super fair skin, so this was not good news considering I’ve been using that bottle all season!

The Experiment – Round 2

Since those results didn’t really make sense to us, we brought in a different bottle of SPF 30 the next day and compared it to the original. We wanted to see if there was a defect with that particular sunscreen, or if SPF 30 really was ineffective.

This time, the new SPF 30 worked as expected, thus leading us to believe that my original Coppertone SPF 30 was either expired or just not very good… Either way, it made for a great learning experience for all of us!

What We Learned

No matter what SPF it is, wear sunscreen! Even the SPF 15, designed to help you tan, blocked some of the sun’s rays for the beads. My kiddos decided that since they don’t want any sunburn, they were wanting to use the SPF 30 or 100. Here’s hoping they don’t complain about reapplying sunscreen this summer. (Parents…you’re welcome. lol)

I hope you and your students will enjoy this fun science experiment as much as we did! It was really exciting to actually “see” how sunscreen works and convince us that we definitely need to be wearing it outside!





Your email address will not be published. Required fields are marked *

Follow My Adventures