Answer: I got you bro. Thunder is heard a few seconds after the flash is seen because sound travels more slowly than light.
Step-by-step explanation:
Flash and thunder are produced simultaneously because they are both part of the same lightning discharge. The flash of light is caused by the rapid movement of electrons within the lightning discharge, while the thunder is caused by the expansion of air that is heated and compressed by the discharge.
Thunder is heard a few seconds after the flash is seen because sound travels more slowly than light. Light travels at a speed of about 299,792,458 meters per second (or about 671 million miles per hour), while sound travels at a speed of about 343 meters per second (or about 767 miles per hour) in air.
Therefore, when you see a flash of lightning, the light reaches your eyes almost instantly, while it takes a few seconds for the sound of the thunder to reach your ears. This is why you hear the thunder a few seconds after you see the flash.