Question

A line in the Balmer series (nf = 2) has a wavelength of 656.3 nm. What is the energy of a mole of photons that has this wavelength?
a) 3.02 x 10⁻19 J
b) 4.48 x 10⁻19 J
c) 6.67 x 10⁻19 J
d) 8.91 x 10⁻19 J