Ammonia is made from its elements in the Haber process. Write a balanced equation for the formation of ammonia in the Haber process.  

Ammonia is made from its elements in the Haber process. For the ammonium ion give formula.

(A) ${{\mathrm{NH}}_4}^{+}$                         (B) ${{\mathrm{NH}}_2}^{+}$                          (B) ${{\mathrm{NH}}_4}^{-}$

Enter your correct answer as A, B or C.

Give the formulae of the following ammonium salt: ammonium chloride.

$$\begin{gathered} \mathrm{A}:{\mathrm{NH}}_3\mathrm{Cl} \\ \mathrm{B}:{\mathrm{NH}}_4\mathrm{Cl} \\ \mathrm{C}:{\mathrm{NH}}_2{\mathrm{Cl}}_2 \end{gathered}$$

(Enter your correct answer as $\mathrm{A}, \mathrm{B} \mathrm{or} \mathrm{C}$)

Give the formulae of the following ammonium salt: ammonium nitrate.

$$\begin{gathered} \mathrm{A}:{\mathrm{NH}}_4{\mathrm{NO}}_2 \\ \mathrm{B}:{\mathrm{NH}}_3{\mathrm{NO}}_3 \\ \mathrm{C}:{\mathrm{NH}}_4{\mathrm{NO}}_3 \end{gathered}$$

(Enter your correct answer as $\mathrm{A}, \mathrm{B} \mathrm{or} \mathrm{C}$)

Give the formulae of the following ammonium salt: ammonium sulphate.

$\mathrm{A}: {\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4\mathrm{B}: {\left({\mathrm{NH}}_4\right)}_3{\mathrm{SO}}_4\mathrm{C}:\hspace{0.17em}\left({\mathrm{NH}}_4\right){\mathrm{SO}}_4$

(Enter your correct answer as $\mathrm{A}, \mathrm{B} \mathrm{or} \mathrm{C}$)

Phosphorus is the element below nitrogen in Group 15 of the periodic table. Its atomic number is $15$. 

Which molecule shows phosphorus in its lowest oxidation state?