Why Iron has Electron shell 2,8,14,2 and why it has valency 2+ instead of 2-

Why Iron has Electron shell 2,8,14,2 and why it has valency 2+ instead of 2-


3 Answers

Aabid Hussain
askIITians Faculty 576 Points
7 years ago
Hi Ayushman,

Iron needs either to accept 6 electron or to loose 2 electrons from the outer shell to fulfill octet condition in the outer most shell. It is easy for Iron to loose 2 valance electron.

Atom is neutral (number of protons = number of electrons). In case of iron, it posseses 2 extra electrons in the outer most shell so its tendency to loose the 2 electrons and hence it becomes 2 units more positive rather than being neutral.
Sagar singh
38 Points
7 years ago
as iron has 26 as its atomic number so the distribution of elcrons shells is 2,8,14,2 because the no. of electrons in the shells are given by the formula 2n^2 so the no. of electrons in the 3rd shell are 18 but acccording the bohr atomic configuration rules the valence shell cannot have more than 8 electrons so we cannot put 18 electrons in valence shell but 2 electrons so that it can form duplet in the valence shell to attain noble gas configuration to become stable.
As the no. of valence electrons = valency (in case of metals only) so when iron will loose the 2 electrons from its outrmost shell at that time the no. of electrons will become less than the no. of protons so it will have more positively charged particles.The sign on valency is +ve when the atom has excess of +vely charged paricles and -ve when the atom has negatively charged particles. as in case of Fe there are more +vely charged particles so it has valency as+2 but not-2.
Umakant biswal
5349 Points
7 years ago
@ ayushman 
as u have mentioned that the electronic configuration of  iron is 2,8,14,2 that is fully correct . 
and what u need to understand is valency is defined as the no. of electrons present in the outermost shell . 
and always element wants to be more stable . so, in this case iron will be stable if it loose 2 electrons rather than gaining 6 electrons and hold it in the valence shell . 
so, by loosing electron iron forms +2 valencies . 

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