Q. Consider the elements Mg. Al, S, P and Si, the correct increasing order of their first ionization enthalpy is :

 2789  228 JEE MainJEE Main 2021Classification of Elements and Periodicity in Properties Report Error

Solution:

In general from left to right in a period, ionistion enthalpy increases due to effective nuclear charge increases.

but due to extra stability of half filled and full filled electronic configuration, required ionisation enthalpy is more from neighbouring elements.

i.e. first ionisation enthalpy order is