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NEET CHEMISTRYStructure of AtomMedium

Question

The number of d-electrons in Fe²⁺ (Z=26) is not equal to the number of electrons in which one of the following?

A

s-electrons in Mg (Z=12)

B

p-electrons in Cl (Z=17)

C

d-electrons in Fe (Z=26)

D

p-electrons in Ne (Z=10)

Step-by-Step Solution

To solve this, we determine the specific electron count for the reference ion and compare it with the options:

  1. Reference: Fe2+^{2+} (Z=26): Electronic configuration of Fe atom: [Ar]3d64s2[Ar] 3d^6 4s^2 . For Fe2+^{2+}, 2 electrons are removed from the 4s orbital: [Ar]3d6[Ar] 3d^6.
  • Number of d-electrons = 6.
  1. Compare with Options:
  • Option A: Mg (Z=12): Configuration is 1s22s22p63s21s^2 2s^2 2p^6 3s^2. Total s-electrons = 2+2+2=62+2+2 = 6. (Equal)
  • Option B: Cl (Z=17): Configuration is 1s22s22p63s23p51s^2 2s^2 2p^6 3s^2 3p^5. Total p-electrons = 6+5=116+5 = 11. (Not Equal)
  • Option C: Fe (Z=26): Configuration is [Ar]3d64s2[Ar] 3d^6 4s^2. Total d-electrons = 6. (Equal)
  • Option D: Ne (Z=10): Configuration is 1s22s22p61s^2 2s^2 2p^6. Total p-electrons = 6. (Equal)

Thus, the number of d-electrons in Fe2+^{2+} (6) is not equal to the number of p-electrons in Cl (11).

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Structure of Atom. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYStructure of Atomnumberdelectronsnumberelectronsfollowing

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