Which is the most thermodynamically stable allotropic form of phosphorus?

For which element will the inert pair effect not be observed?

On heating,lead$(II)$ nitrate gives a brown gas $(A).$ The gas $(A)$ on cooling changes to a colourless solid/liquid $(B).$ $(B)$ on heating with $NO$ changes to a blue solid $(C).$ The oxidation number of nitrogen in solid $(C)$ is :

Which one of the following statements is correct with respect to basic character?

Which of the following statements is $NOT$ true?

Which one of the following compounds on strong heating evolves ammonia gas?