Four consecutive p-block elements in the second period of the periodic table have atomic numbers Z , Z+1 , Z+2 , and Z+3 . Their first ionization enthalpies ( _ i H₁ ) are observed to follow the order: _ i H₁(Z) The outermost electronic configuration of the element with atomic number Z+2 is:

Step-by-step solution

For consecutive p-block elements in the second period, the first ionization enthalpy generally increases with atomic number due to increasing effective nuclear charge. However, an exception occurs between Group 15 and Group 16. Group 15 elements have a stable half-filled p-orbital configuration ( ns ² np ³ ), which requires more energy to remove an electron compared to the ns ² np ⁴ configuration of Group 16 elements. The given order shows a dip where the element with atomic number Z+2 has a lower ionization enthal