Elemental Business: Nitrogen Explosives
Nitrogen - the world's most abundant gas - has brought life and death to humanity on an epic scale - and tragedy to the scientists that have harnessed its power. It is seemingly inert, yet it can also blow things up.
In the first of two programmes on nitrogen, chemistry guru Andrea Sella of University College London explains to Justin Rowlatt how the forces that make this gas so stable are the same ones that make nitrogen compounds such as nitroglycerin so explosive.
Jez Smith, former head of research at the world's biggest explosives firm, Orica, talks about the shocking accuracy of modern mining detonations - all of them based on nitrogen.
And Justin travels to the headquarters of German chemicals giant BASF to learn about ammonia production from Dr Michael Mauss and Bernard Geis, and how the work of chemists Fritz Haber and Karl Bosch a century ago saved the planet from starvation.