The electronic configuration of $\mathrm{Cu}^{2+}$ ion is

• A

  $[\mathrm{Ar}] 3 d^{8} 4 s^{1}$
• Correct answer
  B

  $[\mathrm{Ar}] 3 d^{9} 4 \mathrm{~s}^{0}$
• C

  $[\mathrm{Ar}] 3 d^{7} 4 s^{2}$
• D

  $[\mathrm{Ar}] 3 d^{8} 4 s^{0}$

Solution

Electronic configuration of copper and cupric ion $\begin{aligned} &\mathrm{Cu}(Z=29)=1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{1} \\ &\mathrm{Cu}^{2+} \text { (cupric ion) }=1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{9} 4 s^{0} \end{aligned}$ or

Hence, the correct answer is option: 'B'.