50 Fun Facts About Nitrogen

Nitrogen sits between which two elements in the periodic table?

Carbon and oxygen. Nitrogen, atomic number 7, is the quiet one of the trio: carbon burns and oxygen feeds the fire, while nitrogen gas barely reacts with anything.

Roughly what percentage of Earth's atmosphere is nitrogen?

78%. Yet almost none of it is usable as it stands: plants and animals depend on the small part that soil bacteria have first 'fixed' into compounds.

What is the name for the group of elements headed by nitrogen?

Pnictogens. The same column of the periodic table holds nitrogen and phosphorus, which every living cell needs, and arsenic, notorious as a poison.

Which Scottish physician is credited with discovering nitrogen in 1772?

Daniel Rutherford. He stripped trapped air of its oxygen and carbon dioxide and found that the gas left over put out flames, yet he never realised he had isolated an element.

Which nitrogen-rich fertiliser, left for years in a port warehouse, caused the 2020 Beirut explosion?

Ammonium nitrate. About 2,750 tonnes of it had been taken off a stranded cargo ship and sat in the port for six years before a fire set it off.

What name did Lavoisier propose for nitrogen, meaning 'no life' in Greek?

Azote. It is still the French word for nitrogen, though the name proved ironic: the 'lifeless' gas turned out to be built into every protein and every strand of DNA.

Chaptal named nitrogen after nitre, the gunpowder ingredient better known by which name?

Saltpetre. Chemists had found the gas locked inside it and in the nitric acid made from it, so in 1790 Chaptal coined 'nitrogène', the nitre-former, and English borrowed the word.

What does the German name for nitrogen, Stickstoff, refer to?

Choking or suffocating. The name was coined in 1791 from ersticken, 'to suffocate', because the gas smothers flames, yet it isn't poisonous at all: it simply isn't oxygen.

What kind of bond joins the two atoms in nitrogen gas?

Triple bond. It is so stable that nitrogen compounds release huge energy when they collapse back into the gas, which is why so many explosives are nitrogen compounds.

Which poisonous gas has the only two-atom bond stronger than the one in nitrogen gas?

Carbon monoxide. The two molecules are near-twins, with the same number of electrons and almost the same boiling point, yet one is harmless to breathe and the other is a deadly poison.

Liquid nitrogen boils at −196 °C, which is a tidy 77 degrees on which temperature scale?

Kelvin. The 77 K mark mattered in 1987, when superconductors that work above it were found: they could be chilled with cheap liquid nitrogen instead of a far costlier coolant.

Fertiliser labels list three nutrients as N-P-K: nitrogen, phosphorus and which third element?

Potassium. The K stands for kalium, its Latin name, which like the English word goes back to potash: plant ashes once boiled down in pots and spread on fields.

Short-lived nitrogen-16 in cooling water flags leaks in which kind of plant?

Nuclear power station. Neutrons in the core turn oxygen in the water into nitrogen-16, whose fierce gamma rays fade in seconds, so a trace in the steam flags a leaking tube at once.

Short-lived radioactive nitrogen-13 is used in which kind of medical scan?

PET scan. With a half-life of only ten minutes, the isotope must be made in the hospital's own cyclotron and injected within minutes, typically to map blood flow through the heart.

Lord Rayleigh found that nitrogen taken from air was slightly heavier than nitrogen made from chemicals, revealing which hidden gas?

Argon. The gap was only about half a percent, but Rayleigh and William Ramsay tracked it down, isolating the new gas in 1894, and each won a Nobel Prize for it in 1904.

Every one of which molecules in the human body contains nitrogen?

Amino acids. Each carries a nitrogen-bearing 'amino' group, named after ammonia, and those groups link them into proteins, which is why nitrogen is the fourth most abundant element in the body.

The Haber–Bosch process makes ammonia by combining nitrogen from the air with which other gas?

Hydrogen. Fritz Haber found the conditions and Carl Bosch scaled them up; by 2008 fertiliser made from their ammonia was estimated to feed nearly half the world's people.

Which cheap metal replaced rare osmium as the catalyst of the Haber–Bosch process?

Iron. Haber's own catalyst, osmium, was far too scarce for a factory, so Alwin Mittasch searched systematically for a substitute and settled on iron with a few additives.

Which company's Oppau plant first ran the Haber–Bosch process industrially in 1913?

BASF. The dye maker bought Haber's benchtop method and set its engineer Carl Bosch to scale it up; within four years the Oppau works was making ammonia by the tonne.

In 2008, which nitrogen-rich chemical was added to watered-down Chinese milk to fake its protein content?

Melamine. Milk tests judge protein by counting nitrogen, and melamine is two-thirds nitrogen by weight, so diluted milk passed; six babies died and about 300,000 fell ill.

Carl Bosch shared the 1931 Nobel Prize in Chemistry for taming which extreme condition?

High pressure. His ammonia reactors squeezed the gases inside specially engineered vessels that could take the strain; co-winner Friedrich Bergius used the same kind of pressure to turn coal into liquid fuel.

Which fast-acting poison is an ion made of one carbon atom and one nitrogen atom?

Cyanide. It kills by stopping the body's cells from using oxygen, yet compounds that release it occur naturally in apple seeds, cherry stones and bitter almonds.

Which process turns ammonia into nitric acid for fertilisers and explosives?

Ostwald. His process burns ammonia over hot platinum; fed with synthetic ammonia, it kept Germany making explosives through the First World War after the blockade cut off Chilean nitrate.

Besides bacteria, which natural force fixes nitrogen from the air for plants?

Lightning. The heat of a bolt makes nitrogen and oxygen combine into oxides, though microbes armed with nitrogenase enzymes still do over 90% of nature's fixing.

Rhizobia bacteria fix nitrogen inside the root nodules of which plant family?

Legumes. The plant feeds the bacteria and gets nitrogen in return, which is why farmers rotate peas, beans and clover with hungrier crops to keep the soil fertile.

What is the main nitrogen-bearing waste the human body makes from protein?

Urea. The liver makes it to lock away toxic ammonia; most fish simply shed ammonia into the water, while birds and reptiles save water by excreting uric acid instead.

Alfred Nobel tamed nitroglycerin by soaking it into a fine, absorbent sand to make which explosive?

Dynamite. An explosion at the family works had killed his younger brother Emil and such experiments were banned inside Stockholm, so Nobel moved his work to a barge on a lake.

What is nitrous oxide better known as?

Laughing gas. It is no joke for the climate: pound for pound it traps hundreds of times more heat than carbon dioxide, and most of what people emit seeps from fertilised farm soil.

Which chemist coined the popular nickname for nitrous oxide?

Humphry Davy. He tested the gas on himself in Bristol in 1799 and wrote that it might ease the pain of surgery, yet nobody tried that for another four decades.

Which everyday kitchen product is pressurised with nitrous oxide?

Whipped cream canisters. Sealed in the can, the gas dissolves into the cream's fat, then bubbles back out the moment the nozzle is pressed, puffing the cream into foam.

Oxygen gives the aurora its familiar green, but which colours does nitrogen add?

Blue and purple. Nitrogen's colours are the rarer ones: they tend to show as a fringe along the bottom of the green curtains, and mostly when the Sun is at its stormiest.

Doctors have long used the explosive nitroglycerin as a medicine for which condition?

Angina. It relaxes blood vessels by releasing nitric oxide; weeks before he died in 1896, Alfred Nobel was prescribed it for his own heart and wrote of 'the irony of fate'.

Which explosive, first made in 1863 as a yellow dye, went unrecognised as one for decades?

TNT. It takes a detonator to set it off, so at first nobody realised what it could do; that same stability later let armies melt it and pour it safely into shells.

Which war, begun in 1879, was fought over South America's nitrate deposits?

The War of the Pacific. It began when Bolivia raised taxes on a Chilean nitrate company; Chile went on to seize the whole coast, and Bolivia has been landlocked ever since.

From which language does the word 'guano', for nitrogen-rich seabird dung, come?

Quechua. Spanish took over the Inca word huanu, 'dung', and the stuff became so prized that an 1856 US law let any citizen claim an unowned island with guano on it.

Which explorer studied guano's fertilising power in 1802 and made it known across Europe?

Alexander von Humboldt. At the port where he watched Mercury cross the Sun, he also studied the local fertiliser, and his writings later brought it to Europe's attention.

On deep dives, nitrogen narcosis makes scuba divers feel most like what?

Being drunk. Divers call it the martini effect, and the muddled judgement is what makes it dangerous; unlike a real drink, though, it wears off within minutes once the diver rises to shallower water.

To keep a clear head on very deep dives, divers replace some of their nitrogen with which gas?

Helium. It doesn't dull the brain at depth, but it has drawbacks: it costs far more, chills the diver faster, and makes voices so squeaky that surface crews use unscramblers.

Nitrogen coming out of solution in the blood on rapid ascent causes which condition?

Decompression sickness. Known as the bends, it brings severe pain where bubbles gather in the joints; it also strikes pilots of unpressurised aircraft and workers leaving pressurised caissons.

What is the small nitrogen capsule that lets stout be sold in cans called?

A widget. When the can is opened, the little capsule jets gas and beer out through a pinhole, stirring up the thick, smooth head that a stout otherwise only gets from a pub tap.

Early car airbags inflated with nitrogen gas from the split-second decomposition of which compound?

Sodium azide. A crash sensor fires an igniter and the salt falls apart in about 0.03 seconds, filling the bag with nitrogen; since it is also a potent poison, newer cars use other gas generators.

Which drug works by boosting the effect of nitric oxide, a nitrogen gas the body uses as a signal?

Viagra. That a common air pollutant doubles as a messenger in the body was such a surprise that it won the 1998 Nobel Prize in Medicine; the pill's makers had been hunting for a heart drug.

Which effect, which makes water skitter on a hot pan, briefly shields skin from liquid nitrogen?

Leidenfrost effect. The liquid boils so fast where it touches warm skin that it rides on a cushion of its own vapour; after about a second the cushion fails and the skin starts to freeze.

What happened to an English woman in 2012 after drinking a liquid-nitrogen cocktail?

She had her stomach removed. The liquid boiled inside her, swelling into hundreds of times its volume of gas until her stomach tore; she had been celebrating her 18th birthday.

In January 2024, which US state carried out the first execution by nitrogen gas?

Alabama. The state had tried to execute the same prisoner by lethal injection in 2022 but could not find a vein; a shortage of injection drugs is what pushed states toward nitrogen.

Which moon of Saturn has a dense atmosphere made mainly of nitrogen and methane?

Titan. Its air is mostly nitrogen, like Earth's, but there methane plays the part of water: it gathers in clouds, falls as rain and fills rivers, lakes and seas.

Glaciers of nitrogen ice fill one lobe of the famous heart on which dwarf planet?

Pluto. The nitrogen ice there is soft enough to churn slowly, rising and sinking in cells miles across, and that constant resurfacing is why no crater has been found on the plain.

Nitrogen fertiliser washed down the Mississippi each spring creates what in the sea off Louisiana?

A dead zone. The nutrients feed huge blooms of algae; when the algae die, sink and rot, the decay uses up the oxygen in the water, and fish must flee or die.

Which super-strong fibre is an aramid, a plastic whose long chains are joined by nitrogen-bearing links?

Kevlar. DuPont chemist Stephanie Kwolek found it in 1965 when she had a thin, cloudy solution spun into thread anyway; the fibre proved five times stronger than steel for its weight.

Nitrogen trichloride, an explosive that cost its discoverer an eye, was long used to bleach which food?

Flour. The same compound is behind the 'chlorine' smell of swimming pools, where it forms as pool chlorine reacts with the sweat and urine of bathers.