Conceptual Question

[ELee_3F]

Is this true:

To increase the NUMBER OF ELECTRONS emitted from a surface, you can increase the frequency since E=hv.

&

To increase the ENERGY OF THE PHOTON shot at a surface, you can increase the intensity since intensity is proportional to amplitutde^2 ?

If this is incorrect, could you please correct me? Thanks

[Tamer Siam 2F]

"To increase the NUMBER OF ELECTRONS emitted from a surface, you can increase the frequency since E=hv."
No, remember photons are considered individual packets of light and so one photon can only interact with one electron, therefore increasing the frequency would only increase the kinetic energy of the electron ejected from the surface, not the total number of electrons emitted from one photon.

"To increase the ENERGY OF THE PHOTON shot at a surface, you can increase the intensity since intensity is proportional to amplitutde^2 ?"
This was the initial misconception scientists made before the photoelectric effect. Increasing the intensity merely means sending more packets of light at the surface, and since we established in the previous question that one photon can only interact with one electron, increasing the number of packets being sent wouldn't affect the energy of an individual electron. If you want to increase the energy of the photon, you must increase the frequency.

[Monica Arvizu Madrigal]

Hii! to increase the number of electrons emitted from a surface, you should increase the intensity of the light (which means more photons hitting the surface), as long as the frequency is above the threshold. The energy of each photon is determined by its frequency (E = hv), so to increase photon energy, you need to increase the frequency, not the intensity. Hope that clears things up!