Einstein’s Equation

Einstein proposed that light waves consist of packets of energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit... More called quanta or photons and each photon has an energy, hf.

• h = Plank’s constant (6.63 × 10^-34 Js)
• f is the frequency of the light

That is:

\(\scriptsize E = hf \)

but f = \( \frac{c}{\lambda} \)

∴ E = \( \frac{hc}{\lambda} \)

The incident light must produce enough energy for electrons to overcome the electrostatic force of the metal. The work done by an incident light to remove electrons from a metal is called the work function (W₀ ).

What is Work Function?

Work function (W₀ ) is a metal property referring to the minimum energy needed to liberate an electron from a metal surface. The symbol of work function is Φ.

Different metals have different work functions because It depends on the nature of the metal surface and property of the metal. The electronic structures of different metals vary, meaning the amount of energy required to remove an electron from the surface of a metal is unique to each metal.