The number of the following pairs of elements which exhibit a diagonal relationship is:
$1. B \text{ and } Si$
$2. Be \text{ and } Al$
$3. Li \text{ and } Mg$
$4. Al \text{ and } S$

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. $Al^{3+} < Mg^{2+} < Na^{+} < F^{-}$	$I$. Ionisation Enthalpy
$B$. $B < C < O < N$	$II$. Metallic character
$C$. $B < Al < Mg < K$	$III$. Electronegativity
$D$. $Si < P < S < Cl$	$IV$. Ionic radii

Choose the correct answer from the options given below:

Which of the following statements are correct?
$A.$ The process of the addition of an electron to a neutral gaseous atom is always exothermic.
$B.$ The process of removing an electron from an isolated gaseous atom is always endothermic.
$C.$ The $1^{st}$ ionization energy of boron is less than that of beryllium.
$D.$ The electronegativity of $C$ is $2.5$ in $CH_4$ and $CCl_4$.
$E.$ $Li$ is the most electropositive among elements of group $I$.
Choose the correct answer from the options given below:

Which of the following orders is not correct about the property shown against it?

Point out the wrong statement: On moving horizontally from left to right across a period in the periodic table

Consider the following:
$(I)$ The order of first ionisation enthalpy of the first three elements of the $3^{rd}$ period is $Mg > Al > Na$
$(II)$ The element with an electronegativity of $3.5$ is chlorine
$(III)$ The order of sizes of ions $Mg^{2+}, Na^{+}, F^{-}$ and $O^{2-}$ is $Mg^{2+} < Na^{+} < F^{-} < O^{2-}$
$(IV)$ The $IUPAC$ name of the element with atomic number $106$ is Bohrium.
The correct statements are