# Match the following with their condensed electronic configuration:

$\begin{array} {ll} \text{Element} & \text{Electron Configuration}\\ (1)\; V & a. \; 4s^13d^{10}\\ (2)\; Cr & b. \; 4s^23d^{3}\\ (3)\; Cu & c. \; 3d^1 4s^2 \\ (4)\; Sc & d. 4s^13d^5 \end{array}$

$\begin {array} {1 1} (1) \rightarrow b; \quad (2) \rightarrow a; \quad (3) \rightarrow c; \quad (4) \rightarrow d \\ (1) \rightarrow b; \quad (2) \rightarrow d; \quad (3) \rightarrow a; \quad (4) \rightarrow c \\ (1) \rightarrow a; \quad (2) \rightarrow c; \quad (3) \rightarrow d; \quad (4) \rightarrow b \\ (1) \rightarrow d; \quad (2) \rightarrow c; \quad (3) \rightarrow a; \quad (4) \rightarrow b \end {array}$

Answer: $(1) \rightarrow b; \quad (2) \rightarrow d; \quad (3) \rightarrow a; \quad (4) \rightarrow c$
The elements are in Period 4 so the general configuration is $ns^2(n-1)d^x$
1. V is the third element in the series $\rightarrow 4s^23d^3$
2. Cr is the 4th element in the series but there is an exception made for Cr because the listed electronic configurations are energetically favoured, i.e, $3d^54s^1$ is more stable than $3d^44s^2$
3. Cu is the 9th element in the series but there is an exception made for Cr because the listed electronic configurations are energetically favoured, i.e, $3d^{10}4s^1$ is more stable than $3d^94s^2$
4. Sc is the 1st element in the series $\rightarrow 3d^14s^2$
edited Aug 2, 2014