Apples and Handwashing: "We put a clean apple slice in one jar. We passed another apple slice around the class as we came in from recess with dirty hands. We have been observing the two jars in the science center. This is the difference after 8 days - gross! (This picture doesn't really show the mold.)" - A great way to teach about germs.
"This is the grossest experiment I did while teaching about germs. Use three pieces of bread. You let all the kids see you put a piece of bread in a baggy with a glove on hence "controlled" then you wash your hands and put a piece of bread in a baggy for "clean" last, pass a piece of bread around and let every kid in class touch it then you put it in a baggy and label it dirty. Watch how the bread changes over time. A great way to teach the importance of hand washing."
Creating your own rainstorm...this is so cool! All you need is a clear container, water, shaving cream, food coloring and droppers. Have kids make predictions by drawing what they see and think will happen.