dirty hands bread experiment - what a great way to demonstrate the importance of proper hand washing. Would love to see what happens when you wash hands with warm soapy water versus hand sanitizer! Would make a great science fair project.
Ed Dancing raisins activities. Lots of fun experiments. I have done this experiment, and seen the entire class become silent out of curiosity. It is a great engagement piece for a lesson, and it can be hands on if you ask for volunteers!