## Q. 7.PS.2

Calculating Quantum Energies

In the stratosphere, ultraviolet radiation with a frequency of $1.36 × 10^{15} s^{-1}$ can break $C—Cl$ bonds in chlorofluorocarbons ($CFCs$), which can lead to stratospheric ozone depletion. Calculate the energy per quantum of this radiation.

## Verified Solution

$9.01 × 10^{-19} J$

Strategy and Explanation According to Planck’s quantum theory, the energy and frequency of radiation are related by $E = b\nu$. Substituting the values for $b$ and $\nu$ into the equation, followed by multiplying and canceling the units, gives the correct answer.

$E = b\nu = (6.626 × 10^{-34} J⋅s ) (1.36 × 10^{15} s^{-1} ) = 9.01 × 10^{-19} J$