Why zeff   equivalent to screening effect for Fe Co and ni

Asked by Debdulal | 29th Aug, 2019, 04:46: PM

Expert Answer:

Electronic configuration of first period of d block elements (from Sc to Zn)-
 [Ar]3d1-10 4s2
 
Generally We study Screening effect for valence electrons. when electrons increases in 3d orbitals, these electrons provides more repulsion force to the outermost electrons in 4s. From Sc to Mn, Due to less Number of electrons Repulsion force is not much high so Zeff>screening effect.

In Fe, Co ,Ni  number of electrons in 3d orbitals increases and repulsion force becomes almost equal to attraction of nucleus so screening effect is almost equal to Zeff.
 
In Cu, Zn number of electrons i in 3d orbitals ncreased and It's screening effect becomes higher than Zeff. So in this case Zeff

Answered by Ravi | 30th Aug, 2019, 03:15: PM