NEETChemistryd and f Block Elements
Match List I with List II : List I (Ion) List II (Magnetic Moment) A. Sc ³⁺ I. 4.90 BM B. V ²⁺ II. 2.84 BM C. Cr ²⁺ III. 0.00 BM D. Ni ²⁺ IV. 3.87 BM Choose the correct answer from the options given below :
Options
- AA-III, B-I, C-IV, D-II
- BA-II, B-IV, C-I, D-III
- CA-III, B-IV, C-II, D-I
- DA-III, B-IV, C-I, D-II
Correct answer
D. A-III, B-IV, C-I, D-II
Step-by-step solution
The spin-only magnetic moment is calculated using the formula = n(n+2) BM , where n is the number of unpaired electrons. A. Sc ³⁺ ( Z=21 ): Electronic configuration is [ Ar ] 3d^0 . Number of unpaired electrons n = 0 . = 0.00 BM . (Matches III) B. V ²⁺ ( Z=23 ): Electronic configuration is [ Ar ] 3d^3 . Number of unpaired electrons n = 3 . = 3(3+2) = 15 3.87 BM . (Matches IV) C. Cr ²⁺ ( Z=24 ): Electronic configuration of neutral Cr is [ Ar ] 3d^5 4s^1 . Removing two electrons gives [ Ar ] 3d^4 . Number of unpaired