9. Quantum Mechanics

What is the threshold frequency for sodium metal if a photon with frequency 6.66 × 10¹⁴ s⁻¹ ejects an electron with 7.74 × 10⁻²⁰ J kinetic energy? Will the photoelectric effect be observed if sodium is exposed to orange light?

An ultraviolet photon with a wavelength of 320 nm strikes a metal surface. The emitted electron has a kinetic energy of 3.0 x 10^-2 eV. What is the binding energy of the electron in kJ/mol? 1 electron volt (eV) = 1.602 x 10^-19 J.