## Photon Emission

$c=\lambda v$

104422816
Posts: 17
Joined: Fri Sep 25, 2015 3:00 am

### Photon Emission

Hi, I have a question about emitting photons. I do not know how to solve for that quantity using the equations that we have for energy, wavelength etc. In problems 1.27 and 1.59 they use/ask for the "number of photons given off" that should be equal to the amount of electrons that excite and then drop back down a level but I am unsure how to solve for this.
thanks

Rachel Risoleo 3G
Posts: 19
Joined: Fri Sep 25, 2015 3:00 am

### Re: Photon Emission

Hi! The equation E=hc/lamda gives the "energy per photon." So in problem 1.27 for example, you can find the E/photon using hc/lamda, and then use dimensional analysis to find the number of photons (you can convert the Watts to Joules by multiplying W by the number of seconds, because W=J/s--then use this value in your dimensional analysis). Then you can divide the number of photons by Avogadro's number to find the moles of photons!

Hank Wang 2J
Posts: 25
Joined: Fri Sep 25, 2015 3:00 am

### Re: Photon Emission

For number 59, you just find the energy per photon using hc/lambda and then multiply that energy by 9.8x10^20 to get the total amount of energy.