The Photoelectric Effect

Photoelectric effect

The phenomenon where electrons are emitted from the surface of a metal upon the absorption of electromagnetic radiation.

Photoelectron

Electrons emitted from a metal surface due to the absorption of photons.

Threshold frequency (f₀)

The minimum frequency of incident electromagnetic radiation required to remove a photoelectron from a metal surface.

Work function (Φ)

The minimum energy required to release a photoelectron from the surface of a metal.

Planck's constant (h)

A fundamental constant used in quantum mechanics that relates the energy of a photon to its frequency.

Kinetic energy of photoelectrons (KE(max))

The maximum kinetic energy of emitted photoelectrons, dependent on the frequency of the incident photon.

Intensity of radiation

A measure of the number of photons striking a surface per unit time.

Emission of photoelectrons

Occurs instantaneously when the energy of a photon equals the work function of the metal.

Electromagnetic (EM) radiation

Radiation consisting of oscillating electric and magnetic fields, including light.

Photon energy (E = hf)

The energy carried by a single photon, directly proportional to its frequency.

Quantum mechanics

The field of physics that describes the behavior of matter and energy at the atomic and subatomic levels.

Threshold wavelength

The longest wavelength of incident electromagnetic radiation that can remove a photoelectron from a metal.

Electroscope

An instrument used to detect electric charge, often used to demonstrate the photoelectric effect.

Photoelectric current

The rate of emission of photoelectrons emitted per second, proportional to the intensity of incident radiation.

Electrons in a ‘energy well’

A conceptual analogy for the bound state of electrons within a metal, requiring energy equal to the work function to escape.

Fairground coconut shy analogy

A comparison illustrating the concept of threshold frequency, where low-energy events do not remove obstacles, but high-energy events can.