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.
Thunderstorms can happen anywhere and at anytime as long as the weather conditions are right. These storms most frequently form within areas located at mid-latitude where warm moist air front collides and border cool air fronts. Compared to more active parts of the United States, thunderstorms are relatively rare in Alaska, New England, North Dakota, Montana, and other northern states where the air is generally cold.