Photoelectric Effect

K_{max} = hf - \phi

Maximum kinetic energy of ejected electrons equals photon energy minus the work function.

Variables

K_max

Maximum kinetic energy of electron

Allowed values: 0 or more

Planck constant

Allowed values: greater than 0

J·s

Frequency of light

Allowed values: greater than 0

Work function

Allowed values: greater than 0

Derivation

Explained by Einstein using photon concept, earning him the Nobel Prize.

Your notes

0/5000

Constants in this formula

Planck Constant

6.626 070 15 × 10⁻³⁴. Exact by definition.

J·s

Other modern physics formulas with the same quantities

Photoelectric Threshold Frequency (Quantum Mechanics) shares Work function, Planck constant
de Broglie Wavelength (Quantum Mechanics) shares Planck constant
Particle in a Box Energy Levels (Quantum Mechanics) shares Planck constant
Compton Scattering (Quantum Mechanics) shares Planck constant
Photon Momentum (Quantum Mechanics) shares Planck constant
Electron Wavelength (Accelerated) (Quantum Mechanics) shares Planck constant

Where this formula is listed

Modern Physics formulas, under Quantum Mechanics, alongside Heisenberg Uncertainty Principle, Energy-Time Uncertainty, Time-Dependent Schrödinger Equation, Fermi Energy and Bragg's Law.
In the modern physics list it comes after Photon Energy (Planck) and before Stopping Potential.
Modern Physics formula sheet, one of 41 formulas printed with symbol keys and SI units.
The full formula index, grouped by category and topic.

Common questions

What is the Photoelectric Effect formula?

Photoelectric Effect is written K_max = hf − φ. Maximum kinetic energy of ejected electrons equals photon energy minus the work function. It belongs to Modern Physics, under Quantum Mechanics.

What are the units in K_max = hf − φ?

In SI units, K_max is maximum kinetic energy of electron, measured in J; h is planck constant, measured in J·s; f is frequency of light, measured in Hz; φ is work function, measured in J.

How is the Photoelectric Effect formula derived?

Explained by Einstein using photon concept, earning him the Nobel Prize. The result is K_max = hf − φ.