Match List-$I$ with List-$II$.

List-$I$ (Elements)	List-$II$ (Properties)
$A. Cl, S$	$I. \text{Elements with highest electronegativity}$
$B. Ge, As$	$II. \text{Elements with largest atomic size}$
$C. Fr, Ra$	$III. \text{Elements which show properties of both metals and non-metals}$
$D. F, O$	$IV. \text{Elements with highest negative electron gain enthalpy}$

Choose the correct answer from the options given below:

Which of the following statements are true?
$A.$ Unlike $Ga$ that has a very high melting point,$Cs$ has a very low melting point.
$B.$ On Pauling scale,the electronegativity values of $N$ and $Cl$ are not the same.
$C.$ $Ar$,$K^{+}$,$Cl^{-}$,$Ca^{2+}$,and $S^{2-}$ are all isoelectronic species.
$D.$ The correct order of the first ionization enthalpies of $Na$,$Mg$,$Al$,and $Si$ is $Si > Al > Mg > Na$.
$E.$ The atomic radius of $Cs$ is greater than that of $Li$ and $Rb$.
Choose the correct answer from the options given below

Match List – $I$ with List – $II$

List – $I$ (Element, Atomic number)	List – $II$ (Position in periodic table)
$(a)$ $Ra$ – $88$	$(i)$ $4^{th}$ period, $13^{th}$ group
$(b)$ $Ga$ – $31$	(ii) $6^{th}$ period, $6^{th}$ group
$(c)$ $W$ – $74$	(iii) $5^{th}$ period, $10^{th}$ group
$(d)$ $Pd$ – $46$	(iv) $7^{th}$ period, $2^{nd}$ group

Fill in the blanks given below:
$(i)$ The most widely used scale for measuring electronegativity is ........ .
$(ii)$ The similarity observed in periodic properties is known as .............. .
$(iii)$ The elements located in the middle of the periodic table form .......... type of oxides.

Among the elements $B$,$Al$,$C$,and $Si$,
$(a)$ which element has the highest first ionisation enthalpy?
$(b)$ which element has the most metallic character? Justify your answer in each case.

Which of the following sets is incorrect?