Photoelectric Effect Post-Assessment Question 31A

$c=\lambda v$

Gurkriti Ahluwalia 1K
Posts: 37
Joined: Fri Sep 29, 2017 7:07 am

Photoelectric Effect Post-Assessment Question 31A

31A. If 3.607 x 10^-19 J is required to remove an electron with zero kinetic energy from a metal surface, what would be the longest wavelength light that could do this?

So in other words, we are being asked to find the maximum wavelength where the photons will still have sufficient energy to remove an electron? How do you calculate this? Obviously the minimum is whatever wavelength coordinates with 3.607 x 10^-19 J of E (which i am assuming will be found using e=hv)

MorganYun1H
Posts: 59
Joined: Thu Jul 13, 2017 3:00 am

Re: Photoelectric Effect Post-Assessment Question 31A

The work function is 3.607x10^-19 J.

Also, the longest wavelength that could remove the electron would be when Ek=0.

So you use Ek=h(frequency)-(work function)

Frequency=c/wavelength

0=h(c/wavelength) - (work function)
0=(6.626x10^-34)(3.00x10^8/wavelength) - (3.607x10^-19)

Solve for wavelength.