General Knowledge - Chemistry - Discussion

Discussion Forum : Chemistry - Section 1 (Q.No. 5)
The number of d-electrons in Fe2+ (Z = 26) is not equal to that of
p-electrons in Ne(Z = 10)
s-electrons in Mg(Z = 12)
d-electrons in Fe(Z = 26)
p-electrons in CI(Z = 17)
Answer: Option
No answer description is available. Let's discuss.
30 comments Page 1 of 3.

Osama Shata said:   11 months ago
Fe (Z=26) configuration is [Ar]18 4S2,3d6.

Fe2+ means it will lose two electrons from its outer shell which is 4S.

So the configuration is [Ar]18 4s0, 3d6 . here the Fe2+ is stable because orbitals are fully filled or fully empty. d-electrons Numbers are 6.

Ne10 configuration is 1S2,2S2,2p6. p-electrons Numbers are 6
Mg12 configuration is 4s2,2s2,2p6,3s2 so s-electrons Numbers are 6
Cl17 configuration is 4s2,2s2,2p6,3s2,4p5. After applying half filled orbitals rule, the configuration will be 4s2,2s2,2p6,3s1,3p6 so p-electrons Numbers are 12
So, D is the correct answer.

Desale Moges said:   2 years ago
The electron configuration of Fe+2 will be [Ar]4S13d5.

Maria khan said:   4 years ago
Please give the correct answer description.

M. Ganga rajasree said:   4 years ago
Thanks all for explaining the answer.

M Mishra said:   5 years ago
But I think the question is incorrect, as it asked.

It should be, The number of d-electrons in Fe2+ (Z = 26) is equal to that of.

Satyam Rahul said:   6 years ago
I think option C is right.

Since outer most electron that is in the d orbital there number are 10 and also Fe2+ (Z=26) that's outer most electron numbers are 10 in d orbital.

Gaurav iitian said:   6 years ago
Answer must be option C) Fe (26).

Ktjo said:   7 years ago
I think the answer is B because, when its Mg=12, it is 1s2 2s2 2p6 3S2 but the Fe=26 is 1s2 2s2 2p6 3s2 3p6 4s2 3D6.

Even after you lose one electron from the 'd' of Fe orbital it still is not equal to that of Mg.

Sagarika said:   7 years ago
I think the answer is correct because after D, orbital looses their one electron it stabilised fully.

Ramanuj said:   7 years ago
To start up, the electron configuration of Fe atom is 1s2 2s2 2p6 3s2 3p6 4s2 3d6.

Since the problem is Fe2+ ion, than two electrons are removed from the atom so the correct configuration is 1s2 2s2 2p6 3s2 3p6 3d6.

Likewise, re-check your second configuration. I'm assuming you intended to write it as 1s2 2s2 2p6 3s2 3p6 4s2 3d4. This is incorrect because by then, the element would not be Fe2+ ion. Instead, this would be the electronic configuration of "chromium atom".

Basically, 2 electrons in the 4s orbital are removed because it is much farther away from the nucleus than 3d orbital. Since the electrons in 4s are farther and have weaker pull from the nucleus, there's more tendency for them to be dislodged from the atom.

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