Among the following transition metal ions, how many have the same number of unpaired electrons, and thus approximately the same magnetic moment?

(i) $\mathrm{Cr}^{3+}$

(ii) $\mathrm{Fe}^{3+}$

(iii) $\mathrm{Mn}^{2+}$

(iv) $\mathrm{Co}^{2+}$

(v) $\mathrm{Ni}^{2+}$

The $\mathrm{Fe}^{3+}$ ion, having five unpaired electrons, shows a spin-only magnetic moment closest to

In the following species, how many species have same magnetic moment?

(i) $ \mathrm{Cr}^{2+} $ (ii) $ \mathrm{Mn}^{3+} $ (iii) $ \mathrm{Ni}^{3+} $ (iv) $ \mathrm{Sc}^{2+} $ (v) $ \mathrm{Zn}^{2+} $ (vi) $ \mathrm{V}^{3+} $ (vii) $ \mathrm{Ti}^{+} $

The spin only magnetic moment of $ \mathrm{Fe}^{3+} $ ion (in BM) is approximately.