Question
The correct order of number of unpaired electrons is
A.
$$C{u^{2 + }} > N{i^{2 + }} > C{r^{3 + }} > F{e^{3 + }}$$
B.
$$N{i^{2 + }} > C{u^{2 + }} > F{e^{3 + }} > C{r^{3 + }}$$
C.
$$F{e^{3 + }} > C{r^{3 + }} > N{i^{2 + }} > C{u^{2 + }}$$
D.
$$C{r^{3 + }} > F{e^{3 + }} > > N{i^{2 + }} > C{u^{2 + }}$$
Answer :
$$F{e^{3 + }} > C{r^{3 + }} > N{i^{2 + }} > C{u^{2 + }}$$
Solution :
$$F{e^{3 + }} - 3{d^5}$$ No. of unpaired electrons = 5
$$C{r^{3 + }} - 3{d^3}$$ No. of unpaired electrons = 3
$$N{i^{2 + }} - 3{d^8}$$ No. of unpaired electrons = 2
$$C{u^{2 + }} - 3{d^9}$$ No. of unpaired electrons = 1