The element with atomic number $117$ has not been discovered yet. In which family would you place this element if discovered?

Which of the following pairs has elements containing the same number of electrons in the outermost orbit?

$HClO_4$ 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 $H_2SO_4$.

Which of the following is a metalloid?

Explain the periodic properties of elements and their reactivity trends in the periodic table.

Aluminium is diagonally related to (in periodic table)