50 free Nitrogen trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Nitrogen makes up most of every breath you take, and yet your body cannot use a single molecule of it until lightning, bacteria or a German chemist has broken it apart. This quiz covers element number seven from the air to the fertiliser bag. The easy questions ask what its symbol is, what share of the atmosphere it fills, who first isolated it, how cold liquid nitrogen is and what laughing gas actually is. From there it moves into the chemistry: the triple bond that makes N2 so stubborn, why Lavoisier wanted to call it azote, why the group is called the pnictogens, the two stable isotopes and the radioisotope that lights up nuclear reactor coolant. The harder end is for chemists and history buffs alike: Rutherford's 'noxious air', Chaptal coining nitrogène, Rayleigh's active nitrogen, Haber and Le Rossignol making ammonia drop by drop in 1909, BASF's Oppau plant, the Chilean nitrate fields fought over in the War of the Pacific, guano, Sobrero and Nobel, TNT's life as a yellow dye, Martini's law for divers, the beer widget, airbags, the 2012 liquid-nitrogen cocktail, the first execution by nitrogen and the moon whose sky is thick with the stuff. Every answer was checked against encyclopaedia entries on the element, its compounds and its history, and the supporting sentence is stored with each question. If you enjoy this one, try our periodic table, oxygen and chemistry quizzes next.
30 of 50 questions with answers and explanations. Play the quiz
Q 01What is nitrogen's atomic number?
7
Its symbol is N and it heads group 15 of the periodic table.
Q 02Roughly what percentage of Earth's atmosphere is nitrogen?
78%
Oxygen is about 21% and argon just under 1%.
Q 03What is the name for the group of elements headed by nitrogen?
Pnictogens
The name comes from the Greek for 'to choke', a nod to nitrogen's asphyxiating nature.
Q 04Which Scottish physician is credited with discovering nitrogen in 1772?
Daniel Rutherford
He called it 'noxious air' and distinguished it from Black's 'fixed air', carbon dioxide.
Q 05What later career did nitrogen's discoverer pursue at the University of Edinburgh?
Professor of botany
He was also Regius Keeper of the Royal Botanic Garden Edinburgh from 1786 to 1819.
Q 06What name did Lavoisier propose for nitrogen, meaning 'no life' in Greek?
Azote
It survives in French and other languages and in English words like azide and hydrazine.
Q 07Which French chemist coined the word 'nitrogène' in 1790?
Jean-Antoine Chaptal
He meant the element that 'begets nitre', since nitrogen was found in nitric acid and nitrates.
Q 08What does the German name for nitrogen, Stickstoff, refer to?
Choking or suffocating
Ersticken means to suffocate; Dutch stikstof carries the same idea.
Q 09How many bonds hold the two atoms of an N2 molecule together?
3
The triple bond is among the strongest in any diatomic molecule.
Q 10Which diatomic molecule has the only bond stronger than nitrogen's triple bond?
Carbon monoxide
That strength is why converting N2 into useful compounds is so hard for both organisms and industry.
Q 11At roughly what temperature does nitrogen boil at atmospheric pressure?
-196 °C
It freezes at about -210 °C, and the liquid has about 81% the density of water.
Q 12How many stable isotopes does nitrogen have?
2
Nitrogen-14 makes up 99.634% of the natural element; nitrogen-15 the rest.
Q 13Which isotope is the dominant radionuclide in the coolant of a pressurised water reactor?
N-16
It has a seven-second half-life and its gamma rays are the main way coolant leaks are detected.
Q 14Which isotope, with a ten-minute half-life, is used in PET scanning?
Q 21With whom did Carl Bosch share the 1931 Nobel Prize in Chemistry?
Friedrich Bergius
The prize honoured the introduction of high-pressure methods in chemistry.
Q 22Roughly what share of world food production relied on Haber-process fertiliser by 2010?
About half
Industrial fixation eased a shortage that had rested on mined nitrates and guano.
Q 23Which 1902 method turns ammonia into nitric acid for fertilisers and explosives?
Ostwald
It made large-scale nitrate production possible for munitions in both World Wars.
N-13
It must be made on site in a cyclotron by bombarding oxygen-16 with protons.
Q 15Which physicist discovered monatomic 'active nitrogen' in an electrical discharge in 1910?
Lord Rayleigh
His whirling cloud of brilliant yellow light reacted with mercury to form explosive mercury nitride.
Q 16Nitrogen ranks where among the most abundant elements in the human body by mass?
4th
The body is about 3% nitrogen by mass, mostly in proteins and nucleic acids.
Q 17Which two chemists named the industrial process that turns air nitrogen into ammonia?
Haber and Bosch
It uses finely divided iron as a catalyst and now underpins a huge share of the world's food supply.
Q 18In which year did Haber and Le Rossignol first make ammonia from air, drop by drop?
1909
Their apparatus produced about 125 millilitres an hour.
Q 19Which company's Oppau plant first made Haber-process ammonia industrially in 1913?
BASF
Output reached 20 tonnes a day by 1914, just in time for the First World War's demand for nitrates.
Q 20In what year was Fritz Haber awarded the Nobel Prize in Chemistry for ammonia synthesis?
1918
He actually received it in 1919; Carl Bosch got his in 1931 for high-pressure chemistry.
Q 24Which enzymes let bacteria fix nitrogen from the air?
Nitrogenases
Lightning fixes some nitrogen too, but diazotrophic bacteria do most of the natural work.
Q 25Rhizobia bacteria fix nitrogen inside the root nodules of which plant family?
Legumes
They cannot fix nitrogen without a plant host, which is why peas and clover enrich soil.
Q 26What is the main nitrogen-bearing waste that animals excrete after metabolising protein?
Urea
Breaking down nucleic acids yields uric acid as well.
Q 27Which two nitrogen amines give decaying flesh its characteristic smell?
Putrescine and cadaverine
They come from the breakdown of the amino acids ornithine and lysine.
Q 28What is nitrous oxide better known as?
Laughing gas
It is made by heating molten ammonium nitrate to about 250 °C.
Q 29Which chemist coined the popular nickname for nitrous oxide?
Humphry Davy
Another 44 years passed before doctors tried it for anaesthesia; dentist Horace Wells did so in 1844.
Q 30What everyday kitchen product uses nitrous oxide as a propellant?
Whipped cream canisters
It carries the E number E942 as a food additive.