Question

First ionisation enthalpy of Al is lower than that of Mg. This is because
(a) The size of Al is bigger than Mg
(b) Ionisation enthalpy decreases in a period from left to right
(c) it is easier to remove electron from unpaired 3p' than from paired 352
(d) Aluminium is a passive metal while magnesium is active​

Answer 1

Answer:

(C) it is easier to remove electron from unpaired 3p' than from paired 352

Explanation:

Reason:

Al has one unpaired electron in it's highest energy orbital (3p), and Mg's highest energy orbital (3s) has the paired electrons.

It is energetically favourable for all the electrons in an orbital to be paired, which means that breaking up this pair would require more energy.

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