I love science experiments, and learning new things. Just last week one of my students asked me how long trees can live and how long does it take to get to outer space, and thanks to google I was able to answer him right away. One of my favourite Science topics is learning about Health and Bodies.
We always start our lesson about Health by having the students each take a sprinkle of glitter into their hands. I ask them to then shake hands with another student and they can see the transfer of "germs" to the other. I will ask one student to go wash their hands, and they then can witness the transfer to the tap of the sink and that its difficult to wash the "germs" all off without really washing their hands.