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### worksheet3 question11

Posted: Mon Oct 22, 2018 9:32 pm
Why is a true and d false?

### Re: worksheet3 question11

Posted: Mon Oct 22, 2018 11:31 pm
I'm not really sure about why d is false but for part a, I recall that lavelle briefly mentioned that since UV light has a lower wavelength, therefore a higher frequency and energy than visible or infrared lights, most metals will emit light when a UV light is shone on it. Most metals need this high of a frequency in order for the energy of the light to be greater than the work function of metal.

### Re: worksheet3 question11

Posted: Tue Oct 23, 2018 12:51 am
I assume that for part d, a higher frequency doesn't always imply that the emitted electrons have higher kinetic energies because the frequency has to be within a certain threshold (thus the wavelength has to also be within a certain threshold) in order for electrons to even be emitted.

### Re: worksheet3 question11

Posted: Tue Oct 23, 2018 8:23 am
For part d, higher frequency light has higher energy, so the energy of the photons in that light may be higher than the work function, giving the electrons emitted a higher energy. It is shown by the equation Kinetic Energy of electron=Energy of photon-Work Function. However, not all high frequencies of light will yield an equation where the energy of the photon is higher than the work function. It has to reach a certain threshold.