Explain the reason nitrogen is inert.
Draw a dot-and-cross diagram for a nitrogen molecule. Include only the outer electrons.
Nitrogen, $\text{N}_2$, and oxygen, $\text{O}_2$, react together in the air during lightning strikes to form nitrogen monoxide, $\text{NO}$. Explain why the reaction of $\text{N}_2$ and $\text{O}_2$ happens during lightning strikes.
Write two equations to show how the $\text{NO}$ produced goes on to form nitric acid, $\text{HNO}_3$.
Nitrate fertilisers are used to supply nitrogen for plant growth. If they are used without control, they can reduce the amount of animal and plant life in natural water supplies. Explain how uncontrolled use of nitrate fertilisers can cause this problem.
Some soils are treated with compounds such as ammonium nitrate, calcium carbonate and calcium hydroxide. Suggest why calcium hydroxide is added to some soils.
When calcium hydroxide reacts with compounds containing the ammonium ion, $\text{NH}_4^+$, a gas is made. State what this gas is and explain why the reaction happens.
Another fertiliser, calcium ammonium nitrate, is produced when solid calcium carbonate is added to a mixture of aqueous ammonium nitrate and dilute nitric acid. Suggest what would be observed in this reaction.
Calcium nitrate breaks down at a higher temperature than calcium ammonium nitrate. Write an equation for the thermal decomposition of calcium nitrate.