Which of the following ions gives a coloured solution?

Identify the element if its observed and expected electronic configuration is considered,specifically focusing on the transition metal series where $d$-orbital filling occurs.

Match Column $A$ with Column $B$:

Column $A$	Column $B$
$(1)$ $V^{4+}$	$(a)$ Colorless
$(2)$ $Ti^{3+}$	$(b)$ Pink
$(3)$ $Ti^{4+}$	$(c)$ Purple
$(4)$ $Mn^{2+}$	$(d)$ Blue
	$(e)$ Violet

Identify the correct statements from the following: $(i)$ $Ti(IV)$ is more stable than $Ti(III)$ and $Ti(II)$ $(ii)$ Among $3d-$series elements (from $Z=22$ to $29$) only copper has positive reduction potential $(M^{2+} / M)$ $(iii)$ Both $Sc$ and $Zn$ exhibit $+1$ oxidation state

If the colours of salts of transition elements are due to the presence of unpaired electrons in the transition metal ions,which of the following ions will be colourless in aqueous solution? (The atomic numbers of $Ti$ and $Fe$ are $22$ and $26$ respectively.)

Niobium and tantalum metals are used in making surgical instruments because they are