[camongere]

Hi I am doing some revision on inorganic chemistry and there are a few topics which I can really not get my head around, also I really dont know how to phrase the answers but I will write what I have tried and any help would be appreciated.

example 1.

For a many-electron atom or ion,how is the energy of an orbital related to the effective nuclear charge,Zeff and the principle quantum number,n?

my answer: E=(zeff)squared
                       n

Zeff represents the effective pull on electrons, as Zeff increases the energy of an orbital decreases because Zeff Increases there is a stronger pull from Z on electrons,it is therefore harder to ionise the He atom so orbital energy is lower (Zeff increases going across the group)

also I cant get my head around atomic radii what are the trends and why?

example
Ionic radii
Li+=74
Ag+=115
Rb+=149
q. comment on the values of the ionic radii displayed in the following ions.

my answer: zeff decreases down the group so there for electrons to the centre of the atom so hence the ionic radius increases, also n is greater so the orbitals are larger in size so the electrons are less penetrating.
Zeff increases across the period so the ionic radii decreases because there is more pull on electrons to the centre of the atom however because Ag is isoelectric the shielding is poorer so the ionic radii will be bigger than that of Li+

what am I missing? how do I comment about Li+