What is the photoelectric effect?

The photoelectic effect is when photoelectrons are released from a metal that light is incident upon. The photoelectrons are only emitted when the photons of light are above a certain threshold frequency and energy (called the work function). The energy of the photoelectrons is equivalent to the gaps in electron energy levels of the atoms that compose the metal. Each photon above the work function produces exactly 1 photoelectron and any excess energy is given to the photoelectron in the form of kinetic energy. If the frequency of the light is below the threshold frequency then no photoelectrons are released. 

Answered by Gemma R. Physics tutor

1485 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

Why does a single slit diffraction pattern occur?


An atom can become excited by the absorption of photons. Explain why only photons of certain frequencies cause excitation in a particular atom.


"An inclined plane at an angle of 25 degrees to the horizontal has a pulley at its top. A 30kg block on the plane is connected to a freely hanging 20kg block by means of a cord passing over the pulley. From rest how far will the 20kg block fall in 2s?


Two trains are heading in opposite directions on the same track. Train X has a mass of 16000kg and a speed of 2.8m/s. Train Y has a mass of 12000kg and a speed of 3.1m/s. At what speed do the joined trains move off together immediately after the collison?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences