Which of the following elements has a large jump between its fourth and fifth ionization enthalpies?

Options

A. `Na`
B. `Mg`
C. `A1`
D. `Si`

Answer

D

Explanation

The energy differences between successive steps vary drametically form one element to another as they have different number of valence electrons. It is relatively easy to remove an electron from a partially filled valence shell where `Z_(eff)` is lower, but it is relatively difficult to remove an electron from a filled valence shell where `Z_(eff)` s higher. In other words, there is a large amount of stability associated with filled `s` and `p` subshells (a noble gas electron configuration), which corresponds to having `8` electrons (an octet) in the valence shell of an atom or ion. Thus, sodium `([Ne]3s^(1))]` losser only one electron easily, magesium `([Ne]3s^(2))` losses only two electrons easily, aluminium `([Ne]3s^(2)3p^(1))` losses only three electrons easily and silicon `([Ne]3s^(2)3p^(2))` loses only four electrons easily.