Science Project:

A Beautiful Sunny Day

3.9 based on 14 ratings

  • Does sunscreen block the sun’s ultraviolet radiation?
  • Does a higher SPF number protect skin more than a lower number?

Ozone in the earth’s atmosphere filters out much of the sun’s harmful ultraviolet radiation.Chemicals produced by humans have been harming that protective layer.In the 1970s, scientists noted a thinning of the ozone over Antarctica that grows each spring, increasing the danger of ultraviolet radiation as it shines on earth’s surface and humans.

In this experiment, the independent variable is the sunscreen SPF applied to the plastic.The dependent variable is the exposure of the sun-sensitive paper.The constants include the photo paper, the plastic bags and the conditions.

  • Sunscreens with a range of SPF numbers.For example, 15, 30 and 45 or 15 and 70.
  • Plastic bags—as many as the number of sunscreens plus one for the control.
  • Sun-sensitive paper.(This can usually be found at kids’ stores that stock lots of crafts.)

  1. Close the blinds or shades in a room to block the natural light.
  2. Label the plastic bags with the SPF number for the sunscreen being tested.
  3. Place one square of sun-sensitive paper inside each of the plastic bags.
  4. Place three drops of one sunscreen on the outside of the bag labeled with its number.Spread the sunscreen as evenly as possible.
  5. Repeat the step above with the other sunscreens.
  6. Leave one bag untreated as the control.
  7. Place the bags outside in direct sun, making sure that they receive equal light.
  8. Bring them back inside after 3 minutes or one of the squares—usually the control—turns completely white.
  9. Observe the sun-sensitive squares and make conclusions about the effectiveness of each sunscreen.

The results of the experiment might be visually represented by a modified graph:

Terms/Concepts: Global warming; Ozone; Ultraviolet radiation

Reference:

Author: Jane Healey
Disclaimer and Safety Precautions

Education.com provides the Science Fair Project Ideas for informational purposes only. Education.com does not make any guarantee or representation regarding the Science Fair Project Ideas and is not responsible or liable for any loss or damage, directly or indirectly, caused by your use of such information. By accessing the Science Fair Project Ideas, you waive and renounce any claims against Education.com that arise thereof. In addition, your access to Education.com's website and Science Fair Project Ideas is covered by Education.com's Privacy Policy and site Terms of Use, which include limitations on Education.com's liability.

Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state's handbook of Science Safety.

How likely are you to recommend Education.com to your friends and colleagues?

Not at all likely
Extremely likely