Molybdenum has a work function of 4.2 eV.
Find the cutoff wavelength for the photoelectric
effect. The speed of light
is 3 × 108 m/s and Planck’s constant is
6.626 × 10−34 J · s.
Answer in units of nm.

Calculate the stopping potential if the incident
light has a wavelength of 109 nm.
Answer in units of V.