What are the factors influencing ionization enthalpy.

Explanation

Factors that influencing ionization enthalpy : (i) Size of the atom :
If the size of an atom is larger.
Outermost electron shell from the nucleus is also larger
The outermost electrons experience lesser nuclear force of attraction.
It would be more and easier to remove an electron from the outermost shell.
Thus , ionization energy decreases with increasing atomic sizes.
(ii) Magnitude of nuclear charge :
As the nuclear charge increases , the force of attraction between the nuleus and valence electrons.
(iii) Screening or shielding effect of the inner electrons : Ionization enthalpy decreases when the shielding effect of inner electrons increases . This is because when the inner electron shells increases , the attraction between the nucleus and the outermost electron decreases.
(iv) Penetrating power of subshells s,p,d & f: The penetration power of the electrons in various orbitals decreases in a given shell in the order :s `gtpgtdgtf`.
(v) Electronic configuration : If an atom has half - filled or completely filled sub - levels , its ionization enthlpy is higher . this is because such atoms have stability and hence it is difficult to remove electrons from these stable configuration.