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.

Chemistry and chemical reactions can be electric or explosive, sweet or sour, powerful or perplexing.

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.

Create a carbon dioxide-rich atmosphere in a cup and watch how it changes the water beneath it. This model of ocean–atmosphere interaction shows how carbon dioxide gas diffuses into water, causing the water to become more acidic. Ocean acidification is a change that can have big consequences.

Without much more than a 9-volt battery, you can break water into its two molecular ingredients, hydrogen and oxygen. The four video modules of this hands-on science snack show you how to build a simple electrolysis device and break up water. Using an acid-base indicator, you'll also observe groovy swirls of color in the water as it changes.