Which of the following is a normal element?

Which of the following elements is a metalloid?

In which of the following are the elements in the correct order of their chemical reactivity in terms of oxidizing property?

$HClO_4$ 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 $H_2SO_4$.

All the elements in a group in the periodic table have the same

Arrange the acids $H_2SO_4$,$H_3PO_4$,and $HClO_3$ in the decreasing order of their acidic strength.