The decomposition of a compound into simpler substances with electrical current is called electrolysis. Passing electricity through water–electrolyte solution, hydrogen gas and oxygen gas are obtained. With the Microscale Electrolysis: The Rocket Reaction Demonstration—ChemTopic™ Lab Activity, collect a gas mixture by water displacement, then ignite it with a spark, resulting in a “bulb rocket” shooting across the room. Available as part of the Electrochemistry—ChemTopic™ Labs digital collection. Click the Price link for digital collection pricing.