Question

calculate the effective nuclear charge on the 3d electron of Zn

Answer 1

Am sorry I don't no what is it amswer

Answer 2

For determining the screening constant, S, for an electron, only the electrons in orbitals with a principal quantum number equal to or lower than the principal quantum number of the orbital in which the electron is present are considered. Therefore, in Zn, 4s electrons with n=4, cannot be considered for 3d electrons with principal quantum number 3.

An atomic orbital defines the probable position of an electron. The electron density map of 4s orbital places it closer to the nucleus than 3d orbital. Thus it has a lower energy than 3d orbital and is filled up with electrons before the 3d orbital. This constitutes for only a small part of its probable density map. A 4s electron resides farther away from the nucleus than a 3d electron most of the time. So, although it has a lower energy than 3d, it is unable to shield a 3d electron and hence does not figure in determination of shielding constant.