Question

how does enthalpy of atomisation affect the reduction potential of an element ?

Answer 1

Enthalpy of atomisation is the energy released during the formation of 1 mole of gaseous element from its elements. 

Because electrode potential value depends on the enthalpy of atomisation 

-nFE0 = ΔH0 - TΔS0 

E0 = [ΔH0 - TΔS0/nF] 

The more the enthalpy of atomization the more will be the redox potential that is why the element will have more tendency to undergo reduction.

Answer 2

Ethaply of atomisation is the energy released from the production of 1 mole of gaseous element from its elements. 
Electrode potential value depends on the enthalpy of atomization. The higher the enthalpy of atomization the higher will be the redox potential. Thus it will have more tendency to undergo reduction