The structural formula of hypophosphorus acid is

Phosphine is produced by adding water to

Assertion : Although $PF_5, PCl_5$ and $PBr_5$ are known,the pentahalides of nitrogen have not been observed.
Reason : Phosphorus has lower electronegativity than nitrogen.

Which of the following compounds has a $P-P$ bond?

What are the products obtained when ammonia is reacted with excess chlorine?

Describe the methods of preparation,properties,and uses of dinitrogen gas $(N_2)$.