The element that does $NOT$ exhibit allotropy is$-$

What is the range of oxidation states exhibited by phosphorus?

In an Ostwald process:
$NH_3 + O_2 \xrightarrow[Pt]{\Delta} x + H_2O$
$x + O_2 \to y$
$y + H_2O (excess) \to x + z$
The incorrect option is:

Three allotropes $(A)$,$(B)$ and $(C)$ of phosphorus in the following change are respectively
$A \xrightarrow[1200 \ atm]{470 \ K} B$
$A \xrightarrow[CO_2 - atm]{570 \ K} C$

Consider the following Assertion $(A)$: Phosphorus can form both phosphorus$(III)$ and phosphorus$(V)$ chlorides, but nitrogen cannot form nitrogen$(V)$ chloride. Reason $(R)$: The electronegativity of nitrogen is more than that of phosphorus. The correct answer is

Haber process is used for the production of which of the following?