Question

The number of unpaired electrons in gaseous species of $M{n}^{3+}$, $C{r}^{3+}$, and $V^{3+}$ are ____________ respectively and the most stable species is ______.

• A. 4, 3 and 2;$V^{3+}$
• B. 3, 3and 2$;C{r}^{3+}$
• C. 4, 3 and 2 ; $C{r}^{3+}$
• D. 3, 3 and 3; $M{n}^{3+}$

Answer 1

The correct option is C 4, 3 and 2 ; $C{r}^{3+}$

The no. of unpaired e${}^{-}$ s in the species are:

V${}^{3+}$ - [Ar]3d${}^{2}4s^0$ -2

Mn${}^{3+}$ - [Ar]3d${}^{4}4s^0$ -4

Cr${}^{3+}$- [Ar]3d${}^{3}4s^0$ -3

The most stable species is Cr${}^{3+}$ because Mn${}^{3+}$ will like to readily gain e${}^{-}$ and charge itself into a more stable half filled configuration while V${}^{3+}$ likes to remove two e${}^{-}$s and gain inert gas stable configuration.