Which of the following atoms, in its ground state has the highest number of unpaired electrons?

Question

Aicharya · Accepted Answer

(a) Chromium ( $Z=24$ ) Electronic configuration $(\mathrm{EC})=[\mathrm{Ar}] 3 d^5 4 s^1$

Number of unpaired electrons in $\mathrm{Cr}=6$ (b) Iron $(Z=26)$ $\mathrm{EC}=[\mathrm{Ar}] 3 d^6 4 s^2$

(c) Manganese $(Z=25)$ $\mathrm{EC}=[\mathrm{Ar}] 3 d^5 4 s^2$

(d) Vanadium $(Z=23)$, $\mathrm{EC}=[\mathrm{Ar}] 3 d^3 4 s^2$

Number of unpaired electrons $=3$ So, chromium $(\mathrm{Cr})$ has maximum unpaired electron.

Solution