Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen. Why?

Speed of sound in air (330 m/s) is very less than the speed of light in air (3 × 10⁸ m/s). Hence, although flash and thunder are produced simultaneously, light (flash) reaches the earth's surface a little earlier than sound (i.e., thunder). So thunder is heard a few seconds after the flash is seen.