Question

How many unpaired electrons are there in ${\mathrm{Ni}}^{+2}$?

Answer 1

Electronic configuration:

1. An element's electron configuration describes the distribution of electrons in its atomic orbitals.
2. It tells us the number of lone pairs of electrons, magnetic properties, etc.
3. $\mathrm{Ni}$ has an atomic number$=28$ with electronic configuration$=1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^8$
4. $+2$ charge indicates it has lost two electrons
5. Electronic configuration of ${\mathrm{Ni}}^{+2}=1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^8$ electrons is removed from the lower energy shell.
6. ${\mathrm{Ni}}^{+2}$ has $8$electrons in its outermost shell out of which there are six are paired electrons and two unpaired electrons.

Therefore, the number of lone pairs in${\mathrm{Ni}}^{+2}=2$.