Practice question

Given: Which ion among the following has a 3d⁶ configuration? These values define the system as per NCERT data. Formula: Fe (Z = 26) has 3d⁶ 4s². This is standard NCERT relation. Substitution & Calculation: For Fe^{2+, 2 electrons from 4s are lost, leaving 3d⁶ . Result: The computed value matches expected outcome and confirms correct choice as per NCERT.