Effect of Shielding on Electron Penetration

[garvit21794]

as i have understood, in a many electron atom the degeneracy is lost due to shielding effect. and from quantum mechanical model of one electron atom we can say that keeping principal quantum number(n) fixed, the radius at which radial probability function takes maximum value decreases with increasing angular quantum number(l). then why is it that the 's' shell in many electron atom penetrates more than a 'p' or a 'd' shell and it experiences greater effective nuclear charge.? according to me it should have been the other way around.

 

[Jilang]

as i have understood, in a many electron atom the degeneracy is lost due to shielding effect. and from quantum mechanical model of one electron atom we can say that keeping principal quantum number(n) fixed, the radius at which radial probability function takes maximum value decreases with increasing angular quantum number(l). then why is it that the 's' shell in many electron atom penetrates more than a 'p' or a 'd' shell and it experiences greater effective nuclear charge.? according to me it should have been the other way around.

The p and d shells have experience greater screening than the s shells as they don't penetrate so far in. As you say they have a greater average radius.
http://m.wikihow.com/Determine-Screening-Constant-and-Effective-Nuclear-Charge