Which of the following ionic species will impart colour to an aqueous solution?

Number of paramagnetic ions among the following $d$- and $f$-block metal ions is . . . . . . . $Mn^{2+}$,$Cu^{2+}$,$Zn^{2+}$,$Yb^{2+}$,$Sc^{3+}$,$La^{3+}$,$Gd^{3+}$,$Lu^{3+}$,$Ti^{4+}$,$Ce^{4+}$. (Atomic number of $Mn = 25$,$Cu = 29$,$Zn = 30$,$Yb = 70$,$Sc = 21$,$La = 57$,$Gd = 64$,$Lu = 71$,$Ti = 22$,$Ce = 58$)

Of the following outer electronic configurations of atoms,which one achieves the highest oxidation state?

Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ An element or its ion that does not have a completely filled $d$-orbital is considered a transition element.
$(b)$ $Sc$ is a transition element.
$(c)$ $Zn$ is a transition element.
$(d)$ The energy difference between $(n-1)d$ and $ns$ orbitals is high.

The metal with the highest oxidation state present in $K_2CrO_4$,$NbCl_5$,and $MnO_2$ is

The correct option with the order of melting points of the pairs $(Mn, Fe)$, $(Tc, Ru)$ and $(Re, Os)$ is $:$