Sapling Week 4 #23

[Charlene D 3H]

The electron affinity is the difference in energy between the incident photons and the energy of the ejected electrons. Determine the electron affinity of thulium in units of electron volts per atom.
Note: I didn't include all the values bc I have a conceptual question.

So after finding the difference in energy of the incident photons and the energy of the ejected electrons in eV, my initial thought was to multiply the value by (6.022x10^23 particles/1 atom) because it asks for energy per atom. However, I got the incorrect answer.
When I didn't multiply by the constant my answer was correct. If the problem asks for eV/atom, why do we leave the answer in terms of energy per particle, or is that even the case?
Thank you so much.

[VSU_3F]

Hi Charlene,

You would only need to multiply by Avogadro's number if there asking you to find the electron affinity of a mole of atoms. In the first part, you only need to find the electron affinity of one atom. The electron affinity that you are finding is already in terms of eV per atom, so there is no need to multiply it by any constants. Hope this helped.

Vivien

[Asia Yamada 2B]

In this case, you wouldn’t need to multiply by Avogadro’s number because the electron affinity you found is already for one atom.

[Jose Miguel Conste 3H]

When 1 mole of atoms is being asked, then you multiply by Avogadro's number, but since only 1 atom is being asked you did not need to multiply