Why does thunder accompany lightning

Effect of changing both temperature and pressure on gas volume 

Lightning is one of the most impressive and yet frightening manifestations of nature. It reminds us just how powerful nature can be. 

And we have already seen how air expands when warmed, e.g. as described mathematically by Charles s law (Equation (1.6)). In fact, the air through which the lightning passes increases in volume to an almost unbelievable extent because of its rise in temperature. And the expansion is very rapid. 

8 Show, using the version of Charles s law in Equation (1.8), how a rise in temperature from 330 K to 3300 K is accompanied by a tenfold increase in volume. 

And the reason why we see the lightning first and hear the thunder later is because light travels faster than sound. The reason why thunder accompanies lightning, then, is because pressure p, volume V and temperature T are interrelated. 

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