Question

Rank the 5s, 5p, 5d, 5f, and 5g orbitals in increasing order of their shielding ability.
(A) 5g < 5f < 5d < 5p < 5s
(B) 5g < 5f < 5p < 5d <5s
(C) 5g < 5d < 5f < 5p < 5s
(D) None of these

Answer 1

The shielding effect can be defined as reduction in the effective nuclear charge on the electron cloud, due to a difference in the attraction forces of the electrons in the atom. It is a special case of electric field screening. It decreases with higher orbital energy.

Complete Stepwise solution
The wider the electron shells are in space, the weaker is the electronic interactions between the electrons and the nucleus. The order of the screening effect provided by the electrons in the subshell of the different orbitals are as follows:
s > p > d > f > g.
In short, the greater is the distance of the subshell from the nucleus the lesser will be the screening constant. Depending on the above order, the orbitals in the increasing order of their shielding ability is as follows:
5g < 5f < 5d < 5p < 5s.
So, the correct answer is option A.

Note
The amount of the shielding provided by the electronic shells is difficult to calculate. We can estimate the effective nuclear charge on the electrons after subtracting the effect of the shielding by the electrons by the following formula:
${{\text{Z}}_{\text{eff}}}\text{= Z - }\sigma\text{ }$
Where, $\text{ }\sigma\text{ }$ is called the “shielding constant” which can be determined from Slater's Rules or with the help of the Schrodinger Equation.