General Knowledge - Chemistry - Discussion

Discussion :: Chemistry - Section 1 (Q.No.5)


The number of d-electrons in Fe2+ (Z = 26) is not equal to that of

[A]. p-electrons in Ne(Z = 10)
[B]. s-electrons in Mg(Z = 12)
[C]. d-electrons in Fe(Z = 26)
[D]. p-electrons in CI(Z = 17)

Answer: Option D


No answer description available for this question.

______ said: (Nov 9, 2010)  
Number of d-electrons in Fe2+ and number of p-orbitals in Cl are same...

Balakishan said: (Feb 23, 2011)  
No.of d electrons Fe+2 6(3d6)

no.of p electrons in Ne is 6(2p6),
no.of s electrons in Mg is 6(1s2,2s2,3s2)
no.of d electrons in Fe is 6 (d6)
no.of p electrons in Ci is 11(2p6,3p5)

Auchithya said: (Aug 30, 2011)  
Because if we write firstly the configuration of Fe we get 6 electrons in d-orbital of Fe, but in the question Fe2+is given so we should take of two electrons in the d-orbital of Fe, then we will remain with only 4electrons in d-orbital of Fe. Now if we see options cl will get 4electons in p-orbital.

Deepa335 said: (Nov 5, 2011)  
Actually in d block elements on oxidation d block elements loose electrons first from s orbitals of the outer shell so Fe 2+ will have conf as 4s0 3d6 therefore the answer to the question will b both option A and B

Dipali said: (Dec 1, 2011)  
In case of Fe(Z=26):[Ar]18,3d6,4s2. here is 6 d-orbital.
Fe+2 two ele. will be lose, so Fe+2:[Ar]18,3d5, ele is lost from 4s and one ele. is from 3d orbital it is bcoz if the d-orbital is half filled or fully filled atom will gain more here is 5 ele in d orbital.
Cl(Z=17): 1s2,2s2,2p6,3s2, 5 ele. in p-orbital.
Mg(Z=12): 1s2,2s2,2p6, 2 s-orbital.

Gopalakrishnan said: (Jan 20, 2012)  
In this case, Fe(26)is 1s2,2s2,2p6,3s2,3p6,3d6,4s2...
in Fe2+ is 1s2,2s2,2p6,3s2,3p6,3d5,4s1...because of half-filled configuration is stable... in Ne,Mg,Fe these are elements having full filled configuration and stable configuration.... Cl only having Ne(10) 3s2,3p5..its a unstable configuration...

Kofi said: (Feb 13, 2012)  
Because number of d electrons are the same as the number of p electrons in the p- orbital.

Srinivas said: (Mar 22, 2012)  
Fe 2+ has 6 electrons in d -orbital ,but Cl has 11-electrons in p- orbital

Valli said: (Apr 8, 2012)  
The question should be Fe+2 d electrons are equal to that of so that the answer is D.

Santhoshi Sravya said: (Jun 10, 2012)  
How can you say that cl is having ne[10] and it is unstable configuration.

Clint said: (Oct 28, 2013)  
The question should be stated like this:

"The number of d-electrons in Fe2+ (Z = 26) is equal to that of"

The word "not" should be omitted.

Shikamaru Nara said: (Nov 8, 2013)  
The 4s orbital is at a higher energy level than the 3d orbitals and so because it is Fe(2+) the two electrons both leave the 4s orbital, leaving the 3d orbital with 6 electrons. And so:

No.of p electrons in Ne is 6(2p6).

No.of s electrons in Mg is 6(1s2,2s2,3s2).

No.of d electrons in Fe is 6 (d6).

No.of p electrons in Ci is 11(2p6,3p5).

Sona said: (Apr 30, 2014)  
The number of protons and neutons exist in a nucleus of the ferro magnetic statement amongst ecah of them

Elsa said: (Jun 13, 2014)  
Thanks for answers. The number of d-electron in fe2+ is not equal to that of p-electron in cl.

Dhiraj Mondal said: (Nov 17, 2014)  
After seeing explains, I don't think any other explanation is required.

Sundu said: (Mar 5, 2015)  
What is the molar mass of hydrogen H2?

Okwudike Azubuike said: (Mar 12, 2015)  
Neon is a gas (group 8), Valence electron - 2. Mg and Friday are electro positive metals +2. Click is not equal because it has - 1(2, 8 7). The answer is done.

Narayanam said: (May 17, 2015)  
1s2 2s2 2p6 3s2 3p6 4s2 3d6 is Fe electronic configuration.

While Cl is having 1s2 2s2 2p6 3s2 3p5, so Fe2+ is having configuration as below 1s2 2s2 2p6 3s2 3p6 4s0 3d6.

Sudha said: (Jul 16, 2015)  
P electrons of Ne-2p6, s electron of Mg-3s2, d electron of Fe-3d6 but p electron of Cl is 3p5. So answer may be option D.

Sarawar said: (Sep 1, 2015)  
Actually half filled and full filled orbital are much more stable than partially filled orbital, that is why fe will first loose one electron from d orbital to half filled the 3d orbital then loose one other electron from 4s orbital and become more stable.

Ramanuj said: (Jan 27, 2016)  
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.

Sagarika said: (Jun 17, 2016)  
I think the answer is correct because after D, orbital looses their one electron it stabilised fully.

Ktjo said: (Nov 23, 2016)  
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.

Gaurav Iitian said: (May 17, 2017)  
Answer must be option C) Fe (26).

Satyam Rahul said: (Jul 12, 2017)  
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.

M Mishra said: (Jul 4, 2018)  
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.

M. Ganga Rajasree said: (Dec 27, 2018)  
Thanks all for explaining the answer.

Maria Khan said: (Oct 6, 2019)  
Please give the correct answer description.

Desale Moges said: (Mar 3, 2021)  
The electron configuration of Fe+2 will be [Ar]4S13d5.

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