Which one of the following is the most electropositive element?

Metallic nature and basic nature of the oxides $........$ as we move along a period.

Among the given configurations,identify the element which does not belong to the same family as the others?

The basis of keeping the elements in the same group of a periodic table is

Beryllium shows diagonal relationship with

$HClO_4$ is a stronger acid than $H_2SO_4$ due to which of the following reasons?
$1$. Oxidation state of $Cl$ in $HClO_4$ is $+7$ and that of $S$ in $H_2SO_4$ is $+6$.
$2$. $Cl$ is more electronegative than $S$.
$3$. $HClO_4$ is monobasic,whereas $H_2SO_4$ is dibasic.
$4$. $ClO_3$ part of $HClO_4$ can break $O-H$ bond more easily to liberate a proton than $SO_3$ part in $H_2SO_4$.