[zaerog8]

Hello everyone, I am having a problem figuring out how to find effective nuclear charge (Zeff). I have attached the problems on this post so everyone can see what it the problems look like. I just need to figure how to do the first question so I can figure out others by myself. I tried to attempt this problem by myself but I get really confused easily. I would appreciate anyone who could help me out with this question.

[Borek]

Show what you did so far and where you got lost.

[zaerog8]

So, for question #1, I tried to solve this by plug and chug the numbers into the formula.
First, I convert 1681kJ/mol to 2.79*10^23J/atom
Then,2.79*10^23=2.179*10^(-18)*(Zeff)^2/4
From that, Zeff= 2.26
However, I do not have the actual answers to these problem sets. I was wondering if I was supposed to use second ionization energy and Electron Affinity values to find Zeff.

[Burner]

So, for question #1, I tried to solve this by plug and chug the numbers into the formula.
First, I convert 1681kJ/mol to 2.79*10^23J/atom

Firstly, this conversion is not correct. Check your calculation.

Then,2.79*10^23=2.179*10^(-18)*(Zeff)^2/4
From that, Zeff= 2.26

Do you mean [itex]2.79*10^{23}=\frac {2.179*10^{-18}*(Z_{eff})^2}{4}[/itex] ? If yes, then this is not correct.

Try to determine the energy level of the atom in ground state (E₁, n=1) from the 1^st ionization energy first.

[zaerog8]

Ouch. I'll try to recalculate Zeff again. I'll post again after I attempt this problem again.

[zaerog8]

Ok, so I got my conversion corrected.
1681 kj/mol = 2.79*10^-18
But now I don't know what to do anymore My professor was not teaching this from the textbook and his teaching was so sloppy that I did not understand what he was doing. Please,  provide me a step by step instruction on how to do this problem. I have already read through the textbook, but I still have no clue what to do.

[Burner]

Try to determine the energy level of the atom in ground state (E₁, n=1) from the 1^st ionization energy first.

[zaerog8]

Ok, I managed to figure out how to find effective nuclear charge. Thanks for the advises!!

[zaerog8]

So, here's my solution
Since F+e^-  F^-,
I used Electron Affinity, energy required to accept electron, for the E part in the equation. I converted this from kj/mol into J/atom
The element Fluorine has n=2 so I plugged that into the equation too.
so now I got all the factors except Z_eff filled in, I found out the Z_eff of reaction.