The Work Function Of Sodium,Φ = 2.75eV.
The photon Of Energy, hf = 3.54eV
In photoelectric, the photon energy incident on the surface of the metal is equal to the sum of the work function of the metal and the maximum kinetic energy of the electron.
hf = maximum kinetic energy of the electron + Φ
= The maximum kinetic energy of the electron = hf – Φ
= 3.54eV – 2.75eV = 0.79 eV
Therefore, the kinetic energy of an emitted electron when a photon of energy 3.54eV is incident on the surface of sodium will be 0.79 eV.
Explore more such questions and answers at BYJU’S.