. Write the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?


Best Answer

The factors because of which in elements of the main group the ionization enthalpy decreases when we move down the group are given below:

1. Increase in the shielding effect”: Inner shells increases as we move down the group. Thus, the shielding effect of valence electrons increases by inner core electrons from the nucleus. Thus, the attractive force on electrons towards the nucleus is very strong. So, the energy required to expel a valence electron decreases as we move down the group.

2. Increase in atomic size of elements”: Inner shells increases as we move down the group. Thus, the atomic size increases as we move down the group. Also, the distance between the valence electron and nucleus of an atom, as a result, the electrons are not strongly bounded. So, valence electrons can be expelled easily. Thus, the energy required to expel a valence electron decreases as we move down the group.

 

 

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