Application Of Stater Rules Assignment Help | Application Of Stater Rules Homework Help

Application of Stater Rules

1.    It justifies the filling of ns orbital in preference to (n-1) d-orbital. For example, K has an electronic configuration:
                                                1s2 2s2 2p6 3s2 3p6 4s1
Here Zeff  for for 4s = 19-[(10 x 1.00) + (8 x 0.85)] = 2.20
If the electronic configuration were

Here Zeff for 3d = 19 - [(18x 1.00)+(0.35)] - 1.00.
This shows that a 4s electron experiences a zeff and hence a configuration in which 4s is occupied in preference to 3d would be more stable.

2.    Although stator rules do not allow the exact calculations of the energies of electrons yet these are useful in understanding variation in size, ionization potential and electro negativity.
For example , for an outer electron in elements along the 3rd period, we notice the following tend in Zeff  values :
Element                   P                  S                 CI                Ar                       K
Zeff                            4.80           5.45           6.10          6.75                  (2.2)
This shows that Zeff increases along the period and reaches a maximum at the noble gas which justifies increasing ionization potential along the period with peaking maximum at the noble gas. Ionization potential shows a sudden drop after that as evidenced in  Zeff  value of K.

3. It helps to justify the removal of outer ns-electrons before the removal of inner (n-1) d electrons. For example, it can explain why an outer 5s electronics removed before 4d electron in the case of Ag (Z = 47, 1s2 2s2 2p6 3s2 3p6 3d10, 4s2 4p6 4d10, 5s1). As given in example the effective nuclear change Zeff  for 5s electron is 3.70 and for 4d electron it is 7.85 . This means the 4d electron is held much more strongly by the nucleus (Zeff = 7.85) than the 5s electron (Zeff  = 3.70). This means in the ionization of Ag atom , the electron ionize first form 5s-orbital because these are least tightly held.

For more help in Application of Stater Rules click the button below to submit your homework assignment