Visualize air pressure with the help of a wiggling, wobbling, self-rolling pet toy.
Air molecules are too small to see, so it can be hard to imagine how they can apply forces and create pressure. Self-rolling pet toys can wiggle around erratically, pushing and moving objects a lot like air molecules do, modeling many of the behaviors of the molecules in gases.
Full instructions for this activity are available at https://www.exploratorium.edu/snacks/wiggle-pressure
Science Snacks are hands-on activities, projects, and experiments that are designed for the classroom and the curious. They're cheap, simple, safe, scientifically accurate, and teacher tested. Want to see more? Check out http://exploratorium.edu/snacks.