According to law of photochemical equivalence the energy absorbed (in ergs/mole) is given as (h = 6.62 $$ \times $$ 10^$$-$$27 ergs, c = 3 $$ \times $$ 10¹⁰ cm s^$$-$$1, N_A = 6.02 $$ \times $$ 10^$$-$$23 mol^$$-$$1)

The outer electronic configuration of Gd (At. No. 64) is

The value of Planck's constant is 6.63 $$ \times $$ 10^$$-$$34 J s. The speed of light is 3 $$ \times $$ 10¹⁷ mm s^$$-$$1. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of 6 $$ \times $$ 10¹⁵ s^$$-$$1 ?

What is the maximum numbers of electrons that can be associated with the following set of quantum numbers ?
n = 3, $$l$$ = 1 and m = $$-$$ 1