How does wavelength affect the photoelectric effect?

1 Answer
A08
Mar 12, 2016

Explanation:

Borrowing some material for this answer:

A single photon, whose wavelength is lower than the threshold wavelength for a specific metal, has the required energy to eject one electron thus creating the observed photoelectric effect.

Einstein used Planck's famous expression #E = hnu#, to explain other experimental results of photoelectric effect.

#E# being energy, #nu#, the frequency of radiated energy and #h# is Planck's Constant. We know that speed of light in vacuum #c# is related to its frequency #nu# and wavelength #lambda#

#c=nulambda#

Einstein put forward the following equation:

#(hc)/lambda_text{ incident}=phi+KE_max#

where #h# is Planck's constant, #lambda_text{ incident}# wavelength of incident light, #phi# work function of the metal and #KE_max# the maximum kinetic energy of the ejected electron(s).

chemistry-batz.wikispaces.com
For photoelectric effect to occur, the energy of the photon must be greater than the work function.
#phi=(hc)/lambda_text{ cut-off}#

As the wavelength of the incident light decreases but is lower than the cut-off wavelength, the maximum kinetic energy of the photo electrons increases.

Related questions
See all questions in The Dual Nature of Light
Impact of this question
37454 views around the world
You can reuse this answer
Creative Commons License