Question

$\mathbf{O}\mathbf{,}\mathbf{}{\mathbf{O}}^{\mathbf{+}}\mathbf{,}\mathbf{}{\mathbf{O}}^{\mathbf{-}}\mathbf{,}\mathbf{}\mathbf{Os}\mathbf{,}\mathbf{Zr}\mathbf{,}\mathbf{S}\mathbf{,}\mathbf{F}\mathbf{,}\mathbf{Ar}$How many unpaired electrons are present in each of the following in the ground state:?

Short answer

The total number of valence electrons present in$\mathrm{O},{\mathrm{O}}^{+},{\mathrm{O}}^{-},\mathrm{Os},\mathrm{Zr},\mathrm{S},\mathrm{F},\mathrm{Ar}$ are $2,3,1,4,2,2,1$and 0 .

Step-by-step solution

Step 1:

ATOM ELECTRONIC CONFIGURATION

1. $\mathrm{O}1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^2$
   
2. ${\mathrm{O}}^{+}1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^3$
   
3. ${\mathrm{O}}^{-}1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^5$
   
4. $\mathrm{Os}\left[\mathrm{Xe}\right]4{\mathrm{f}}^{14}5{\mathrm{d}}^{6}6{\mathrm{s}}^2$
   
5. $\mathrm{Zr}\left[\mathrm{Kr}\right]4{\mathrm{d}}^{2}5{\mathrm{s}}^2$
   
6. $\mathrm{S}\left[\mathrm{Ne}\right]3{\mathrm{s}}^{2}3{\mathrm{p}}^2$
   
7. $\mathrm{F}\left[\mathrm{He}\right]2{\mathrm{s}}^{2}2{\mathrm{p}}^5$
   
8. $\mathrm{Ar}\left[\mathrm{Ne}\right]3{\mathrm{s}}^{2}3{\mathrm{p}}^6$
   

Step 2:

$\mathrm{O},{\mathrm{O}}^{+}$and${\mathrm{O}}^{-}$ have $2,3$and unpaired $1$electron in their $2\mathrm{p}$orbital.

$\mathrm{Os}$has $4$unpaired electrons in its $5\mathrm{d}$orbital.

$\mathrm{Zr}$has $2$unpaired electrons in its $4\mathrm{d}$orbital.

$\mathrm{S}$has $2$unpaired electrons in its $3\mathrm{p}$orbital.

$\mathrm{F}$has $1$unpaired electrons in its $2\mathrm{p}$orbital.

$\mathrm{Ar}$has no unpaired electron and its octet is complete.