Consider the following elements $In$,$Tl$,$Al$,$Pb$,$Sn$ and $Ge$. The most stable oxidation states of elements with highest and lowest first ionisation enthalpies,respectively,are

Identify the correct statements from the following.
$(i)$ In the periodic table,about $78 \%$ of elements are metals.
$(ii)$ In a group,the metallic character decreases from top to bottom and in a period the nonmetallic character decreases from left to right.
$(iii)$ The element $Ho$ belongs to $f-$block.

Which of the following statements is not correct regarding the classification of elements in the periodic table?

Match the properties of elements given in List-$I$ with List-$II$.

List-$I$	List-$II$
$(1)$ Active non-metal with high electron gain enthalpy.	$(A)$ $Na$
$(2)$ Soft metal with low ionization enthalpy.	$(B)$ $Sb$
$(3)$ Metalloid that forms ${M_2}{O_3}$ type oxide.	$(C)$ $He$
$(4)$ Chemically inert gas.	$(D)$ $Cl$

The change in enthalpy $[\Delta H]$ in $kJ\ mol^{-1}$ for the reaction is $Mg + 2F \rightarrow MgF_2$. Given: $EA$ of $F = 328\ kJ\ mol^{-1}$, $IE_1$ of $Mg = 737\ kJ\ mol^{-1}$, $IE_2$ of $Mg = 1451\ kJ\ mol^{-1}$.

The cause of the diagonal relationship is: