Contributed By: Chemistry for Life
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Experiment Category:
Objective:
Don’t burn your buns! Discover how sunscreen saves your skin.
What You Need:
- Sliced rings of an apple (you might want an adult to help!)
- Some string
- A coat hanger
- Cheesecloth (optional)
- A sunny spot
To Do and Observe:
Slice your apple into rings about 0.5cm (¼ inch) thick (you’ll need at least 2 rings). Loop the string around each apple ring so you can hang them Hang your apple rings from the coat hanger - make sure they don’t touch! Loosely drape the cheesecloth over your hanger and apple rings to discourage bugs. Hang your coat hanger in a sunny place. Check on your apple rings after a couple hours, then a day or two. Compare them to a freshly cut apple ring.
What's Going On:
You can see how powerful the sun can be, even though it might look harmless. The apple rings dried out - the same thing can happen to your skin if you don’t protect it when you’re in the sun. In addition to preventing sunburn, sunscreens include moisturizers to help keep your skin from drying out and becoming itchy.
Parent/Teacher Tips:
Ask your child if he/she thinks putting sunscreen on the apple slices would help keep them from drying out. Make a hypothesis (an educated guess about what you think will happen), and try the experiment again with sunscreen on one apple ring, keeping one ring without sunscreen as your control. Make sure you label which one has the sunscreen. Is anything different about the rings? Are they the same color? Did the sunscreen protect the apple? Did you coat both sides of your ring with sunscreen? Do you think it would make a difference if you used different types of sunscreen - different SPF (sun protection factor), or oil instead of lotion? Sun protection factor is the measure of how many times longer a person can stay in the sun using sunscreen than if they didn’t wear any at all. So, if you can normally stay in the sun for 30 minutes before you start to burn, an SPF 4 sunscreen would allow you to stay in the sun 2 hours before you started to burn (four times longer than without any sunscreen).