Question

The work function of a metal is 4.50 eV. Find the frequency of light to be used to eject electrons from the metal surface with a maximum kinetic energy of 6.06 × 10⁻¹⁹ J.

Answer 1

Maximum kinetic energy of photoelectron = Energy of incident photon − Work function

Or, 6.06 × 10⁻¹⁹ = hv − 4.5 × 1.6 × 10⁻¹⁹

Or, hv = 13.26 × 10⁻¹⁹

Or, v = `((13.26 xx 10^-19))/((6.6 xx 10^-34))`

∴ v = 2 × 10¹⁵ Hz