The Exploratorium is a 21st-century learning laboratory and museum based in San Francisco. Since 1969, we’ve offered visitors and learners around the world the opportunity to experience everyday scientific phenomena firsthand through creative, thought-provoking exhibits, educational tools, and programs. We promote an inquiry-based approach to learning—one that ignites curiosity about the world around us, encourages exploration, and leads to profound discoveries.
The science "snacks" on this website are fun, hands-on activities developed and thoroughly tested by the Exploratorium Teacher Institute. Dive in and discover what we're all about!
These hands-on activities investigate phenomena that arise from molecules and atoms interacting and transforming in different ways. Build a battery and light up an LED without much more than the change in your pocket.
Can you light up a room with just five cents?
A battery is a device that converts chemical energy into electrical energy. This activity, developed and demonstrated by Julie Yu, director of the Exploratorium Teacher Institute, shows you how to build a battery strong enough to power an LED for a whole day—using nothing more than a few pennies and a salty solution.
Watch the videos to learn how to build a battery of your very own, and light the way for other chemistry lovers.