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.
GR
Related Physics A Level answers
All answers ▸Explain the difference between forced vibration and resonance in an oscillating object.
Define the terms "acceleration" and "displacement". Explain simple harmonic motion with reference to both of these quantities.
How can we explain the standing waves on a string?
Atmospheric Pressure is about 1.0x10^5 Pa. What is the downward force of the air on a desktop of surface area 1m^2?