### Homework question 1.27

Posted:

**Fri Apr 27, 2018 9:14 am**How would we calculate moles of photons in homework problem 1.27?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=14&t=31136

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Posted: **Fri Apr 27, 2018 9:14 am**

How would we calculate moles of photons in homework problem 1.27?

Posted: **Fri Apr 27, 2018 11:05 am**

Once you have the number of electrons emitted in 2 seconds, you can just divide that by Avogadro's constant to get the moles of electrons emitted in 2 seconds.

Posted: **Sun Apr 29, 2018 4:11 pm**

And to find the number of photons, use the equation E=hc/wavelength. then take the total Energy (64J) and divide that by the Energy you just found (which is J/photon --> 473x10^-19) to get the number of photons which is 1.35x10^20 photons.

Posted: **Sun Apr 29, 2018 5:16 pm**

Just divide the number you found that's emitted in two seconds by Avogadro's number (6.02*10^23) since there are that many atoms in just a single mole. Hope this helped! :)