ight energy can be described as nhf , where n is a number of photons, h is Planck's constant, and f is the frequency of the light, also denoted by the symbol ???? . Calculate the minimum number of photons, n , needed to make the reduction of 2 moles of NADP+ favorable for light absorbed at 680.000 nm . Assume that the amount of energy needed for the reduction of one mole of NADP+ to be favorable must exceed 219 kJ/mol .