The strongest reducing agent among the following is:

Which of the following statements is $NOT$ true for both white and red phosphorus?

Given below are the two statements: one is labeled as Assertion $(A)$ and the other is labeled as Reason $(R)$.
Assertion $(A)$: There is a considerable increase in covalent radius from $N$ to $P$. However,from $As$ to $Bi$,only a small increase in covalent radius is observed.
Reason $(R)$: Covalent and ionic radii in a particular oxidation state increase down the group.
In the light of the above statements,choose the most appropriate answer from the options given below:

The number of oxygen atoms bonded to one phosphorus atom in $P_4O_6$ is

Pure $N_2$ gas is obtained from which of the following?

With reference to protonic acids,which of the following statements is correct regarding the basicity of $PH_3$ and $NH_3$?