Why do we first see lightning during a thunderstorm, and only then do we hear the thunderclaps?

To answer this question, you need to turn to the very nature of the phenomena and the ways of perceiving these phenomena by man. Both of these phenomena appear as a result of the creation of a huge electrical discharge in the clouds, lightning itself is the light that is emitted after this discharge, and thunder is the sound that accompanies this discharge. Let us turn to the speed of propagation of light (300 thousand k / s) and sound (331 m / s), from here we can see that the speed of light is several times higher than the speed of sound, and if we take into account that we observe lightning at a certain distance from it, therefore we see her earlier, because the speed of light is significantly higher than the speed of sound.