In which pair of ions are both diamagnetic in nature?

Which of the following options represents the increasing order of the paramagnetic property of the ions?

Which one of the following has a magnetic moment of $1.75 \ BM$?

Which of the following pairs has the same size?

Fill in the blanks:
$(a)$ The ground state electronic configurations of $Cr$ and $Cu$ are .......... and ..........,respectively.
$(b)$ Transition elements exhibit certain characteristic properties due to partially filled $d$-orbitals.
$(c)$ The general electronic configuration of transition elements is .......... .

Match the following:

$I. \ Zn^{2+}$	$(i) \ d^8 \ \text{configuration}$
$II. \ Cu^{2+}$	$(ii) \ \text{Colourless}$
$III. \ Ni^{2+}$	$(iii) \ \mu = 1.73 \ \text{BM}$