Question

The valence shell electronic configuration of $C{r}^{2+}$ ion is

• A. $3p^{2}4s^2$
• B. $4s^{2}3d^2$
• C. $4s^{2}3d^0$
• D. $4s^{0}3d^4$

Answer 1

Answer: (D)

Electronic configuration of chromium
$Cr\to \left[Ar\right]3d^{5}4s^1$
$C{r}^{+2}\to \left[Ar\right]3d^{4}4s^0$