Energy of Photon = Work Function

SnehinRajkumar1L
Posts: 101
Joined: Thu Jul 11, 2019 12:15 am

Energy of Photon = Work Function

What happens when the energy of the photon is equal to the work function? How is the electron emitted if there is no excess energy to be converted into kinetic energy?

xenamclean_1G
Posts: 51
Joined: Sat Jul 20, 2019 12:15 am

Re: Energy of Photon = Work Function

If they are equal (the energy of the photon and the work function), then electrons are not emitted even for high intensity light.

Baoying Li 1B
Posts: 113
Joined: Sat Aug 17, 2019 12:18 am

Re: Energy of Photon = Work Function

If a photon has an energy equals the work function, the photon energy can be transferred to the electron and the electron will have enough energy to escape from the metal. The kinetic energy will be zero.

AKatukota
Posts: 100
Joined: Thu Jul 25, 2019 12:18 am

Re: Energy of Photon = Work Function

Unless the E(Photon) is greater than or equal to the E(Energy to remove an electron), an electron will not be emitted even for HIGH INTENSITY light, which was quite unexpected in the photoelectric effect experiment. Light sources with long wavelength (low frequency) light does not eject electrons even with this high intensity light.

Junwei Sun 4I
Posts: 125
Joined: Wed Oct 02, 2019 12:16 am

Re: Energy of Photon = Work Function

When energy of the photo is equal to energy of the work function the electron will still get ejected since the energy of the photon reaches the threshold energy, which is the minimum amount of energy needed to remove an electron from the metal surface. I was confused at this concept too of ejected electrons having KE=0, but my guess is that since the detector has a slightly positive charge it draws the ejected electron towards it even when KE=0.