The values of electronegativity of atoms $A$ and $B$ are $1.20$ and $4.0$ respectively. The percentage of ionic character of $A-B$ bond is ............. $\%$

The non-metal that does not exhibit a positive oxidation state is

If the ionization enthalpy and electron gain enthalpy of an element are $275$ and $86 \ kcal \ mol^{-1}$ respectively,then the electronegativity of the element on the Pauling scale is

The molecule with the most polar bond is:

Keeping in view the periodic law and the periodic table,suggest which of the following elements should have the maximum electronegative character.

Aqueous solutions of two compounds $M_1OH$ and $M_2OH$ are prepared in two different beakers. If the $EN$ of $M_1 = 3.4$,$EN$ of $M_2 = 1.2$,$EN$ of $O = 3.5$,and $EN$ of $H = 2.1$,then the nature of the two solutions will be: