What is the total number of unpaired electrons in an element placed at period-4 and group-12 either in…
What is the total number of unpaired electrons in an element placed at period-4 and group-12 either in excited or at ground state?
Zero
One
Two
Three
Solution
Zn belongs to period 4 and group 12 of the periodic table.
$\begin{aligned}
& \mathrm{Zn}(\text { ground state })=[\mathrm{Ar}] 3 \mathrm{~d}^{10} 4 \mathrm{~s}^2 \\
& \mathrm{Zn}^{2+}(\text { excited state })=[\mathrm{Ar}] 3 \mathrm{~d}^{10}
\end{aligned}$