Question

plz show me how to do it :!

Answer 1

Energy of 1 photon = planck's constant(h) x frequency(ν)                                                               = 6.626 x 10⁻³⁴ x (5 x 10⁵)
                               = 3.313 x 10⁻²⁸J
Energy of 1 mole of photons     = Avogadro number(6 x 10²³) x 3.313 x 10⁻²⁸
                                                  = 6 x 10²³ x 3.313 x 10⁻²⁸
                                                  = 19.8 x 10²³⁻²⁸
                                                  = 1.98 x 10⁻⁵Joules

So the answer is none of these, but if the frequency would have been
5 x 10¹⁵Hz, then the answer would have been (B).