Ionization Potential, Ionization potential energy effective nuclear charge
Ionization potential energy effective Nuclear Charge
Hligher the effective nuclear charge more tightly the electrons are bound to the nucleus and higher is the ionization potential energy.
Ionization potential in Atomic size: Bigger the atom less tightly the outermost electrons are bound to the nucleus. Hence lower is the ionization potential energy.
Ionization potential effect of orbitals
Beryllium and nitrogen in thesecond period and magnesium and Phosphorus in the third period have ionization potential energy higher than the expected value.
Reason: This is because in the case of Be and Mg, the s subshell (2s and 3srespectively) are completely filled. In the case of nitrogen and phosphorous the 2p and3p orbitals are half-filled orbitals. Completely filled or half-filled orbital arrangements are more stable. Hence breaking of these stabler configurations require higher energy.So the ionization energy of nitrogen containing half-filled 2p orbitals is greater than that Of oxygen. Similarly the ionization energy of phosphorus containing half-filled 3p orbitalsis more than that of sculpture.
Effect of Inert gas configuration: The inert gas configuration of ns2np6 is highlystable. Hencebreaking of this arrangement requires extremely high energies. So all theinert gases have very high ionization energies.
Effect of removal of s, p, d and f electrons from the same energy shell: The holdby the nucleus on the electrons of different subshells of a given principal leveldecreases in the following orders> p > d > f. Hence the ionization energy for pulling out. An electron from the given energy level decreases in the order of s, p, d and f orbitals.Examples: The first ionization potential of magnesium involving removal of 3s is moredifficult than removing an electron from 3p orbital of aluminium.
Effect of ionic size and electronic configuration on higher ionization potential energies: The second and the higher ionization potentials depend on two factors: Duringsuccessive ionizations, captions of smaller and smaller size result. The effective nuclearcharge also increases. Due to this, successive ionization energies increase. At any stage of ionization, if an ion attains a half-filled configuration or a completely filled electronicconfiguration of an inert gas, then, for the next higher ionization, very high values areobserved.