The spin-only magnetic moment value of M^3+ ion (in gaseous state) from the pairs Cr^3+ / Cr^2+, Mn^3+ / Mn^2+, Fe^3+ / Fe^2+ and Co^3+ / Co^2+ that…

The spin-only magnetic moment value of $\displaystyle \mathrm{M}^{3+}$ ion (in gaseous state) from the pairs $\displaystyle \mathrm{Cr}^{3+} / \mathrm{Cr}^{2+}, \mathrm{Mn}^{3+} / \mathrm{Mn}^{2+}, \mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}$ and $\displaystyle \mathrm{Co}^{3+} / \mathrm{Co}^{2+}$ that has negative standard electrode potential, is \_\_\_\_ B.M. [Nearest integer]