Question

A certain shade of blue has a frequency of 7.15 × 1014 hz. what is the energy of exactly one photon of this light?

Answer 1

The energy carried by a single photon of frequency f is given by:
$E=hf$
where $h=6.6 \cdot 10^{-34} m^2 kg s^{-1}$ is the Planck constant. In our problem, the frequency of the photon is $f=7.15 \cdot 10^{14}Hz$, and by using these numbers we can find the energy of the photon:
$E=(6.6\cdot 10^{-34}m^2 kg s^{-1})(7.15 \cdot 10^{14}Hz)=4.7 \cdot 10^{-19}J$