Which of the following ions exhibit same value of spin only magnetic moment?
(A). $\text{Ti}^{3+}$
(B). $\text{Cr}^{3+}$
(C). $\text{Mn}^{2+}$
(D). $\text{Fe}^{3+}$
(E). $\text{Sc}^{3+}$
Choose the most appropriate answer from the options given below.

Which of the following cations in their oxidation states forms colored compounds ?

What is the atomic number of an element having $ns^1$ electronic configuration and belonging to 3d transition series?

Which of the following elements is doped to a fiber amplifier in an optical fiber communication system?