Neet Solved Paper 2015 Question 24
Question: The number of d-electrons in $ F{e^{2+}},(Z=26) $ is not equal to the number of electrons in which one of the following?
Options:
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) $
Show Answer
Answer:
Correct Answer: B
Solution:
- Electronic configuration of $ F{e^{2+}} $ is $ [Ar]3d^{6}4s^{0}. $
$ \therefore $ Number of electrons = 6 $ Mg-1s^{2}2s^{2}2p^{6}3s^{2} $ (6d electrons) It matches with the 6d electrons of $ F{e^{2+}} $ $ Cl-1s^{2}2s^{2}2p^{6},3s^{2}3p^{5} $ (11p elections) It does not match with the 6d electrons of $ F{e^{2+}} $ . $ Fe-[Ar]3d^{6}4s^{2} $ (6d electrons) It matches with the 6d electrons of $ F{e^{2+}}. $ $ Ne-1s^{2}2s^{2}2p^{6} $ (6p electrons) It matches with the 6d electrons of $ F{e^{2+}}. $ Hence, $ Cl $ has 11p electrons which does not matches in number with 6d electrons of $ F{e^{2+}}. $
