It takes 258 kJ/mol to eject electrons from a certain metal surface. What is the longest wavelength of light (nm)that can be used to eject electrons from the surface of this metal via the photoelectric effect?
A)464
B)233
C)165
D)725
E)552

Question

Quizplus · Accepted Answer

The energy required to eject electrons is given by E = hc/λ, where h is Planck's constant and c is the speed of light. Solving for λ, λ = hc/E. Substituting the given energy (258 kJ/mol = 258,000 J/mol) and constants, the longest wavelength is approximately 464 nm.

It Takes 258 KJ/mol to Eject Electrons from a Certain