Explain the features that influence/affect the ionization energy.

Explanation

(1) Effective Nuclear charge :- If effective nuclear charge increases lionization energy decreases.
(2) Atomic Size :- If atomic size increases lionization energy increases.
(3) Half or completely filled orbitals : - From Half or completely filled orbitals , starting high IE.
(4) Orbital of same energy : If orbitals having the same principle quantum number n,
(5) Shielding (Screening) Effect :- Inner electrons repel the outer valence electrons . They reduce the nuclear force.