A device that creates an electric current by stripping electrons from hydrogen molecules is called a

• A. Battery
• B. Generator
• C. Fuel cell
• D. Solar panel

Answer: (C)

Hydrogen fuel cells convert chemical energy directly into electrical energy through an electrochemical reaction. At the anode, hydrogen molecules are oxidized, releasing electrons: H2 -> 2H+ + 2e-. The electrons flow through an external circuit, creating electric current, while the protons move through the electrolyte to the cathode. At the cathode, they combine with oxygen and the incoming electrons to form water: O2 + 4H+ + 4e- -> 2H2O. This setup continues as long as hydrogen and oxygen are supplied, producing electricity with water as the main byproduct.

This is distinct from a battery, which stores chemical energy and releases it as electricity until the reactants are depleted; from a generator, which uses mechanical energy to produce electricity via induction; and from a solar panel, which uses light to generate electricity through the photovoltaic effect.