Question

What is the longest wavelength of light that will emit electrons from a metal whose work function is 3.50 eVeV

Answer 1

Longer wavelength means less energy. When less energy, less electrons emit from a metal surface. When no kinetic energy, it means no electrons emit.

K = 0 due to the less energy of light.

E = W + K

hc/wavelength = (3.50eV) + (0)

hc/3.50eV = wavelength

Wavelength = (6.63 x 10^-34)(3 x 10^8)/(3.50 eV)