Chemistry

Question Analysis
This question involves comparing second ionization energies of isoelectronic cations.
The main focus is on linking electron configuration, nuclear charge, and successive ionization energy for ions with the same electron count.

Key Concept Explanation
Isoelectronic species have identical electron configurations but different nuclear charges.
Second ionization energy for these cations involves removing an electron from the [Ne] core configuration (Na⁺, Mg²⁺, Al³⁺ all have [Ne] electron configurations).
A lower nuclear charge results in weaker attraction to core electrons, making them easier to remove (lower ionization energy).

Step-by-Step Solution
1. Confirm the electron configuration of all three ions: [Ne] (1s²2s²2p⁶).
2. ...