Science Club - monitoring UV light rays using UV beads

First we threaded UV beads onto pipe cleaners.We found the UV beads stayed white when we exposed them to the classroom lights.

However, the UV beads turned bright colours when exposed to the sun.  They are made of a chemical which changes colour in the presence of UV rays.  People's skin changes colour too, from  brown or even red if we are exposed to the sun for too long a time.

We placed some UV beads into a plastic bag and smothered it in 30+ sunscreen.  We found that the UV beads changed from white to very subdued colours when they were protected by a layer of sunscreen.  Next time, we will experiment with 50+ sunscreen to see if that blocks out 100% of harmful UV rays.