Video Demo: Laser Lens Eye

Teaching how the eyeball works usually involves showing diagrams of the eyeball and showing how light passes through the lens. Science teachers can also use Jello to make lenses that will show laser light refraction.  I tried that and had disastrous results.  I started to play around with mixing baby powder (mostly cornstarch) with red food coloring and water.  I was quite pleased with the results.  Go ahead and watch the video below to see what happens.

Video Demo: Glowing Tonic Water Fountain

The idea for this demo came from Steve Spangler Science.  In his post he states:

Tonic water might not be your first choice for a beverage, but it's the secret ingredient you'll need to make a glowing geyser. It turns out that tonic water will glow under a black light because tonic water contains quinine, a chemical that was originally added to tonic water to help fight off malaria in places like India and Africa. While the tonic water we drink today only contains a small amount of quinine, it's still enough to make your drink glow under black light. 

Instead of using mentos to make a glowing gyser, I decided to do a Hero's fountain version. You can get a simple apparatus from teachersource.com that fits into 2 2L bottles. Where in your curriculum can you fit this? In eighth grade science we cover properites of matter such as denisty, phase at room temperature, color, flame color, smell, texture, etc.  Some chemicals can be identified from the ability to fluoresce when exposed to uv light. I would maybe do this with a fountain of regular water and one with tonic water and then ask the students if the same chemical is in each founatin.