Which pair of elements exhibits a diagonal relationship in the periodic table?

Count the number of properties which have higher value for '$O$' atom than that of '$S$': Ionisation potential, Electron affinity, Covalent radius, Electronegativity.

The set of elements that differ in mutual relationship from those of the other sets is:

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.

In which of the following options the order of arrangement does not agree with the variation of property indicated against it?

An element $E$ has an ionisation enthalpy value of $374 \ kJ \ mol^{-1}$. $E$ reacts with elements $A, B, C$ and $D$ with electron gain enthalpy values of $-328, -349, -325$ and $-295 \ kJ \ mol^{-1}$,respectively. The correct order of the products $EA, EB, EC$ and $ED$ in terms of ionic character is $:$