Question

What are the exceptions to the trend in ionization energy

Answer 1

Exceptions to the trend in ionization energy can be observed in periods 1 and 2 of the periodic table between groups 2 and 3, and again between groups 5 and 6. These exceptions can be explained by looking at the electron configurations of the atoms involved.

Step-by-step explanation:

Exceptions to the trend in ionization energy can be observed in periods 1 and 2 of the periodic table. In these periods, there are decreases in ionization energy between groups 2 and 3, and again between groups 5 and 6. These exceptions can be explained by looking at the electron configurations of the atoms involved.

For example, as you move from magnesium to aluminum, one electron is added to the 3p subshell. This electron is slightly further from the nucleus and is therefore easier to remove compared to the 3s electrons. The decrease between phosphorus and sulfur occurs because the added electron in sulfur is the first to be paired in the p subshell, leading to repulsion and making the sulfur atom slightly less stable than expected.

Answer 2

The two exceptions from the general trend are the ionization energies of B lesser than Be and that of O

Step-by-step explanation:

less than N. My teacher told me the reason to both was that half filled and fully filled orbitals of N and Be are more stable and hence require more energy to pull off an electron.