Electronic configuration (comparison): The number of d-electrons in Fe²⁺ (Z = 26) is not equal to which of the following electron counts? Evaluate total counts for p- or s-electrons stated for other atoms/ions. Choose the correct option.
IIT JEE
Chemistry
Difficulty: Medium
Choose an option
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Ap-electrons in Ne (Z = 10)
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Bs-electrons in Mg (Z = 12)
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Cd-electrons in Fe (Z = 26)
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Dp-electrons in Cl (Z = 17)
Answer
Correct Answer: p-electrons in Cl (Z = 17)
Explanation
Step-by-StepFe: [Ar] 3d64s2; Fe²⁺ = 3d6 ⇒ 6 d-electronsNe: 1s² 2s² 2p⁶ ⇒ total p-electrons = 6Mg: 1s² 2s² 2p⁶ 3s² ⇒ total s-electrons = 2 + 2 + 2 = 6Fe (neutral): 3d⁶ ⇒ 6 d-electronsCl: 1s² 2s² 2p⁶ 3s² 3p⁵ ⇒ total p-electrons = 6 + 5 = 11Only Cl's p-electron count (11) ≠ 6.
Final Answerp-electrons in Cl (Z = 17)