Which of the following elements is a metalloid?

Which reaction is not feasible?

Identify the correct order of basicity for the following oxides: $Na_2O, MgO, CuO, SiO_2$.

$HClO_4$ 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 $H_2SO_4$.

Based on the provided periodic table segment,identify the correct statement regarding the oxide of element $X$. The element with atomic number $Z = 52$ is Tellurium $(Te)$.

Which of the following is a normal element?