In which of the following,the tendency towards the formation of coloured ions is maximum?

Which of the following metal ions is colourless?

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

The transition elements have a characteristic electronic configuration which can be represented as:

Which of the following transition metals has the lowest density?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A):$ $Cu^{2+}$ in water is more stable than $Cu^{+}$.
Reason $(R):$ Enthalpy of hydration for $Cu^{2+}$ is much less than that of $Cu^{+}$.
In the light of the above statements,choose the correct answer from the options given below: