Questions: What is Ionization energy? What is the periodic trend of ionization energy across a period and within a group? Explain the factors affecting Ionization energy? On which factors ionization energy depends upon?
I have already answered two of your questions in previous blogs which i have written few months before. You can find out answers via below links:
- Define Ionization Energy.
- Explain Ionization energy.
- What is the trend of ionization energy across a period and within group?
- Why Ionization energy increases across a period?
- Why Ionization energy decreases within group?
- Differentiate between Ionization energy and electron affinity.
Factors Affecting Ionization Energy
The magnitude of ionization energy increases with net binding force exerted on the electron being ionized. This force, in turn, is determined by a number of factors, many of which are interrelated. We make only a brief mention of these factors.
Effective nuclear charge
The effective nuclear charge experienced by the electron under consideration is the most important factor controlling ionization energy. Z(eff) depends on the nuclear charge Ze as well as on the screening provided by other electrons. The extent of screening is again related to a number of factors to be mentioned below.
The radial distance of the orbital from which the electron is being removed, naturally affects the magnitude of I. The greater the effective distance the easier it will be to remove the electron. We know that radial distance is primarily determined by the principal quantum number n.
Extent of penetration
The extent of penetration of outer orbitals into the inner electron core effect screening. Penetration depends on, among other things, on n or l of an orbital.
Relative stabilities of electrons configuration before and after ionization also contribute significantly to the magnitude of I. In fact, several factors are responsible for such stabilities, for example simple electron repulsion, spin correlation, exchange energy and, of course, overall energy for the relevant electron configuration.