CHARLES D. WINTERS / SCIENCE PHOTO LIBRARY CHARLES D. WINTERS / SCIENCE PHOTO LIBRARY
Electrolysis of water using a Hoffman apparatus. Electrolysis is the use of an electrical current to decompose a chemical, in this case water. Reactions at the two electrodes (black hooks dipped in the beaker of water) are powered by the electric current from the battery (lower left). Oxygen and hydrogen gas bubbles are evolved at the anode (left electrode) and cathode (right electrode) respectively. As water molecules consist of two hydrogen atoms and one oxygen atom, twice as much hydrogen as oxygen is trapped in the test tubes (upper right). Use of a burning splint will ignite the hydrogen gas, while the oxygen will relight a glowing splint.
Model release not required. Property release not required.