### Theory:

Chemical reactivity:

Nitrogen is inactive at normal conditions. It does not combine with elements at normal conditions, but it combines with elements at high temperature and pressure or in the presence of a catalyst.

Combustibility:

Nitrogen is neither combustible nor support for combustion. Hence, nitrogen in the air moderates the rate of combustion.

Reaction with metals:

Nitrogen reacts with metals such as lithium ($$Li$$), calcium ($$Ca$$), magnesium ($$Mg$$) (these metals are called electropositive metals), etc., at high temperature and form their corresponding metal nitrides (ionic nitrides).

Note: Electropositive means tend to lose electrons to form positive ions.

$\mathit{Metal}+\mathit{Nitrogen}\phantom{\rule{0.147em}{0ex}}\stackrel{\mathrm{\Delta }}{⟶}\phantom{\rule{0.294em}{0ex}}\mathit{Metal}\phantom{\rule{0.147em}{0ex}}\mathit{nitride}$

Example:

$\begin{array}{l}6\mathit{Li}+{N}_{2}\stackrel{\mathrm{\Delta }}{⟶}\phantom{\rule{0.147em}{0ex}}{\mathit{2Li}}_{3}N\phantom{\rule{0.147em}{0ex}}\left(\mathit{Lithium}\phantom{\rule{0.147em}{0ex}}\mathit{nitride}\right)\\ \mathit{3Ca}{+N}_{2}\stackrel{\mathrm{\Delta }}{⟶}\phantom{\rule{0.147em}{0ex}}{\mathit{Ca}}_{3}{N}_{2}\phantom{\rule{0.147em}{0ex}}\left(\mathit{Calcium}\phantom{\rule{0.147em}{0ex}}\mathit{nitride}\right)\end{array}$

Reaction with non-metals:

Nitrogen reacts with non-metals such as hydrogen ($$H_2$$), oxygen ($$O_2$$) etc., at high temperature to form their corresponding nitrogen compounds.

$\mathit{Non}-\mathit{metal}+\mathit{Nitrogen}\stackrel{\mathrm{\Delta }}{⟶}\phantom{\rule{0.147em}{0ex}}\mathit{Nitrogen}\phantom{\rule{0.147em}{0ex}}\mathit{compound}$

Example:

$3{H}_{2}\left(\mathit{Hydrogen}\right)+{N}_{2}\phantom{\rule{0.147em}{0ex}}\left(\mathit{Nitrogen}\right)\phantom{\rule{0.147em}{0ex}}\stackrel{\mathrm{\Delta }}{⟶}\phantom{\rule{0.147em}{0ex}}2{\mathit{NH}}_{3}\left(\mathit{Ammonia}\right)$