Answer :
(a) The nitrogen atom of [tex]NH_2^-[/tex] would have 8 electrons around the central nitrogen atom.
(b) The nitrogen atom of [tex]NH_4^+[/tex] would have 8 electrons around the central nitrogen atom.
(c) The nitrogen atom of [tex]NH_3[/tex] would have 8 electrons around the central nitrogen atom.
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
Now we have to determine the number of electrons present around the central nitrogen atom of the following molecule.
(a) The given molecule is, [tex]NH_2^-[/tex]
As we know that nitrogen has '5' valence electrons and hydrogen has '1' valence electron.
Therefore, the total number of valence electrons in [tex]NH_2^-[/tex] = 5 + 2(1) + 1 = 8
According to Lewis-dot structure, there are 4 number of bonding electrons and 4 number of non-bonding electrons.
From the Lewis-dot structure we conclude that the nitrogen atom of [tex]NH_2^-[/tex] would have 8 electrons around the central nitrogen atom.
(b) The given molecule is, [tex]NH_4^+[/tex]
As we know that nitrogen has '5' valence electrons and hydrogen has '1' valence electron.
Therefore, the total number of valence electrons in [tex]NH_4^+[/tex] = 5 + 4(1) - 1 = 8
According to Lewis-dot structure, there are 8 number of bonding electrons and 0 number of non-bonding electrons.
From the Lewis-dot structure we conclude that the nitrogen atom of [tex]NH_4^+[/tex] would have 8 electrons around the central nitrogen atom.
(c) The given molecule is, [tex]NH_3[/tex]
As we know that nitrogen has '5' valence electrons and hydrogen has '1' valence electron.
Therefore, the total number of valence electrons in [tex]NH_2^-[/tex] = 5 + 3(1) = 8
According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.
From the Lewis-dot structure we conclude that the nitrogen atom of [tex]NH_3[/tex] would have 8 electrons around the central nitrogen atom.
