Which element does not show the inert pair effect?

How many isotopes of nitrogen are found in nature?

When $NH_3$ is passed over heated $CuO$,what is it oxidized to?

Which of the following statements are correct?
$(I)$ $P_4$ molecule is very reactive because of angular strain.
$(II)$ The basicity of $H_3PO_3$ is $3$.
$(III)$ In gas phase,all $P-Cl$ bonds of $PCl_5$ have same bond length.
$(IV)$ In solid state,$PCl_5$ exists as an ionic solid,in which anion $[PCl_6]^-$ has octahedral and cation $[PCl_4]^+$ has tetrahedral shape.

In $P_4O_6$,how many oxygen atoms are attached to each phosphorus atom?

Match the List-$I$ with List-$II$.

List-$I$ (Family)	List-$II$ (Symbol of Element)
$A$. Pnictogen (group $15$)	$I$. $Ts$
$B$. Chalcogen	$II$. $Og$
$C$. Halogen	$III$. $Lv$
$D$. Noble gas	$IV$. $Mc$

Choose the correct answer from the options given below: