This is called rectification, and rectifier diodes are most commonly used in low current power supplies. A switching diode is most often used to turn a circuit on or off, and band switching diodes are used for switching high frequency band signals.
Thunder occurs when energy from lightning heats and rapidly expands the air. The resulting sound wave gets heard as thunder. While lightning and thunder occur at roughly the same time, lightning travels at the speed of light, or at 186,000 miles a second, while thunder travels at the speed of sound, equivalent to one-fifth of a mile in one second. People see the lightning long before they hear the thunder.
Every thunderstorm produces lightning, which kills more people than tornadoes each year. Thunderstorms also cause heavy rain, flash flooding, hail, strong winds and tornadoes. When warm and cold air masses meet, a thunderstorm can grow. In this activity, you will learn about convection and how air moves.