Why does lightning conduct through air

Lightning is one of the more impressive manifestations of the power in nature the sky lights up with a brilliant flash of light, as huge amounts of electrical energy pass through the air. 

The source of the light seen with an electric discharge is the plasma formed by the electricity, which is a mixture of ions and electrons, and unionized atoms. If, for example, we look solely at nitrogen, which represents 78 per cent of the air, an electric discharge would form a plasma comprising N2 1 , N+, electrons e, nitrogen radicals N, as well as unreacted N2. Incidentally, the formation of these ions explains how air may conduct electricity. 

The electron affinity measures the attractive force between the incoming electron and the nucleus the stronger the attraction, the more energy there is released. The factors that affect this attraction are exactly the same as those relating to ionization 

Care do not confuse the symbols for electron affinity E(ea) and activation energy Ea from kinetics (see Chapter 8). 

The negative value of (ea) illustrates how the energy of the species X (g) is lower than that of its precursor, X(g). 

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