Which statement is wrong for $NO$?

An orange solid $(X)$ on heating,gives a colourless gas $(Y)$ and a green residue $(Z).$ Gas $(Y)$ on treatment with $Mg,$ produces a white solid substance. Identify the white solid substance.

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.

Which of the following oxides of nitrogen is not a common pollutant in the atmosphere?

What are the boiling points of nitrogen and oxygen gases?

Write a note on allotropes of phosphorus.