Hello,

I am referring to this problem

http://grephysics.net/ans/8677/26

I understand the solution (it's very easy) but that equation, where there's Z-B

where B is to account for the screening effect, such that B=1 for S and B=7.4 for L.

My question: Where can I find this specific piece of detail about the screening effect?

I have Serway's Modern Physics but I cannot find it anywhere there...

Thanks !