Chapter 4, Problem 15P

The sodium D-line is actually a pair of closely spaced spectroscopic lines seen in the emission spectrum of sodium atoms. The wavelengths are centered at 589.3 nm. The intensity of this emission makes it the major source of light (and causes the yellow color) in the sodium arc light.

(a) Calculate the energy change per sodium atom emitting a photon at the d-line wavelength.

(b) Calculate the energy change per mole of sodium atoms emitting photons at the d-line wavelength.

(c) If a sodium arc light is to produce 1.000 kilowatt $\left(\text{1}000{\text{ J s}}^{-\text{1}}\right)$ of radiant energy at this wavelength, howmany moles of sodium atoms must emit photons per second?