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maximum frequency

How would you work this out, we get given Ek Max + work function = hf

and I know work function = h threshold frequency

here's the question, I thought you just did change in E=hf therefore fmax= delta E/ h

I got 2.171945701x10^15Hz, answer should be 1.9x10^15Hz

Reply 1

usycool1

Original post by Lay-Z

I got 2.171945701x10^15Hz, answer should be 1.9x10^15Hz

This has nothing to do with the photoelectric effect so the work function equation is completely irrelevant here. The question is about excitation and de-excitation of atoms.

The kinetic energy of the electron in the higher energy level is 9.0eV. After the collision, the electron moves to the 1.0eV orbital and because it moves to a lower energy level, it emits a photon.

Now the energy carried by the photon is equal to the difference in the two energy levels of the electron (so in this case, 8.0eV).

So you need to convert 8.0eV to Joules and then plug this value into the E = hf equation to get the frequency of the photon. :smile: