## Post Module #19

Rebecca Cheung 1E
Posts: 20
Joined: Fri Sep 29, 2017 7:04 am

### Post Module #19

Which one of following is not describing the photoelectric effect?

A. E (photon) – E (remove e-) = E (excess)
B. E (photon) – E (remove e-) = EK (e-)
C. hv - work function = 1/2mv2
D. λv = c
E. None of the above

What is the answer to this and can someone explain why? Thanks!

Sammy Thatipelli 1B
Posts: 63
Joined: Thu Jul 27, 2017 3:01 am
Been upvoted: 1 time

### Re: Post Module #19

The photoelectric effect shows that light (electromagnetic radiation) acts as particles with particle-like properties. Therefore, d would not explain the photoelectric effect because d is an equation for wave-like properties, like wavelength.

Posts: 57
Joined: Fri Sep 29, 2017 7:04 am

### Re: Post Module #19

I believe the answer is D! A, B, and C all describe the same equation, which has to do with the photoelectric effect. The equation for D was not derived as a result from the photoelectric experiment!

Michael Koger 3K
Posts: 21
Joined: Fri Sep 29, 2017 7:07 am

### Re: Post Module #19

In order to understand the question, it is necessary to understand how the photoelectric effect works. Basically, light is shone on a metal, and the metal emits electrons. However, the appropriate frequency and therefore energy of light that is needed to knock off electrons is different for every substance. Answers A, B, and C all depict how the energy of a photon is used to remove an electron (with the excess energy existing as the kinetic energy of the emitted electron). Answer D is simply depicting the relationship between the wavelength and frequency of light, so it is the correct answer.