Identify the element from following having six unpaired electrons in observed electronic configuration?

Identify the element from following having six unpaired electrons in observed electronic configuration?
  1. $\mathrm{Cu}$
  2. $\mathrm{Zn}$
  3. $\mathrm{Cr}$
  4. $\mathrm{Ti}$

Solution

Chromium (Cr): Expected electronic configuration: $[\mathrm{Ar}] 3 \mathrm{~d}^4 4 \mathrm{~s}^2$ Observed electronic configuration: $[\mathrm{Ar}] 3 \mathrm{~d}^5 4 \mathrm{~s}^1$ Hence, number of unpaired electrons in observed electronic configuration is 6 .

Asked in: MHT CET 2023 (09 May Shift 2)

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