Which ion is not coloured?

Match the following:

List-$I$	List-$II$
$A$. Titanium	$I$. Non-metal
$B$. Fluorine	$II$. Transition metal
$C$. Tellurium	$III$. Lanthanoid
$D$. Dysprosium	$IV$. Metalloid

The electronic configurations of four elements are:
$(i) \; [Xe] \; 6s^1$
$(ii) \; [Xe] \; 4f^{14}5d^16s^2$
$(iii) \; [Ne] \; 3s^23p^5$
$(iv) \; [Ar] \; 3d^74s^2$
Which one of the following statements about these elements is not true?

Which from the following series of elements is $CORRECTLY$ arranged according to their decreasing order of ionization enthalpy $(IE_1)$?

Cuprous ion is colourless while cupric ion is coloured because

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.