Chapter 30 - Quantum Physics - Problems and Conceptual Exercises - Page 1076: 90

$3.69\times 10^{28}photons$

The number of photons can be calculated as follows: $E_{photon}=\frac{(6.63\times 10^{-34}J.s)(3\times 10^8m/s)}{(12.2cm)(\frac{10^{-12m}}{1cm})}$ $E_{photon}=1.63\times 10^{-24}J$ Now $n=\frac{Q}{E_{photon}}$ We plug in the known values to obtain: $n=\frac{6.01\times 10^4}{1.63\times 10^{-24}}$ $n=3.69\times 10^{28}~photons$