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60 free Carbon trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This carbon trivia quiz covers the element that makes life possible and shows up as everything from pencil lead to diamond. The easy questions handle the basics: its symbol and atomic number, how many bonds it forms, why graphite is soft and diamond is hard, and where the name comes from. The harder end gets into the details: the isotopes and how carbon-14 dating works, why no carbon was made in the Big Bang and how stars build it three helium nuclei at a time, the fullerenes that won a Nobel Prize, graphene, lonsdaleite and Q-carbon, Lavoisier burning a diamond to prove what it was, the Borrowdale graphite that made the first pencils, where kimberlite pipes are found, and why 'diamonds are forever' is technically untrue. Every answer was checked against the element's encyclopaedia entry before publishing and the supporting sentence is stored with each question. Our periodic table, chemistry, hydrogen and oxygen quizzes are the natural next stop.
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Q 01What is carbon's atomic number?
6
Its symbol is C and it sits in group 14 of the periodic table with silicon and germanium.
Q 02Carbon is described as tetravalent. How many covalent bonds can each atom form?
Four
Its outer shell holds four electrons, which is why it builds such an enormous variety of molecules.
Q 03The name carbon comes from the Latin word for what?
Coal
German, Dutch and Danish are blunter still: Kohlenstoff, koolstof and kulstof all mean 'coal-substance'.
Q 04Carbon ranks where in abundance among elements in the universe by mass?
Fourth
Only three lighter elements outweigh it; more than 20% of cosmic carbon may be tied up in polycyclic aromatic hydrocarbons.
Q 05Carbon is the second most abundant element in the human body by mass. Which element comes first?
Oxygen
Most of that oxygen is in water, while carbon forms the backbone of proteins, fats, sugars and DNA.
Q 06Under normal conditions, which three carbon materials have the highest thermal conductivities known?
Diamond, nanotubes and graphene
Diamond is also the hardest natural material known, yet it barely conducts electricity.
Q 07Graphite gets its name from a Greek verb meaning what?
To write
It is soft enough to leave a streak on paper because its hexagonal sheets slide past one another.
Q 08In graphite, each carbon atom is bonded to how many others within its flat sheet?
Three
The sheets stack loosely through weak van der Waals forces, which is why graphite is soft and slippery.
Q 09Why is 'diamonds are forever' technically untrue?
They should slowly turn into graphite
At high temperatures the change happens fast; diamonds can burn up in a house fire.
Q 10What is a two-dimensional sheet of carbon atoms in a hexagonal lattice called?
Graphene
As of 2009 it appeared to be the strongest material ever tested, though separating it cheaply from graphite is still a challenge.
Q 11Fullerenes and buckyballs are named after which architect?
Richard Buckminster Fuller
His geodesic domes resemble the molecules' structure; the best-known buckyball is the soccerball-shaped C60.
Q 12Fullerene was discovered in 1985. Its discoverers Curl, Kroto and Smalley won which honour in 1996?
The Nobel Prize in Chemistry
The find revived interest in new allotropes and led to glassy carbon and the realisation that 'amorphous' carbon is not truly amorphous.
Q 13How many atoms are in buckminsterfullerene, the simplest and best-known buckyball?
60
Its cells include pentagons as well as hexagons, which warps the sheet into a sphere.
Q 21In 1961, IUPAC adopted which isotope as the basis for atomic weights?
Carbon-12
Before that, oxygen had served as the reference standard.
Q 22Carbon nuclei are forged in stars by which fusion route?
The triple-alpha process
Three helium nuclei must collide almost at once, because the two-step intermediates lithium-5 and beryllium-8 fall apart instantly.
Q 23Why was no significant carbon created in the Big Bang?
It expanded and cooled too fast
The process needs temperatures above 100 megakelvins and a helium concentration the young universe never sustained.
Q 14Which carbon allotrope, found in 1997, is ferromagnetic and among the lightest solids at about 2 kg per cubic metre?
Carbon nanofoam
Its atoms are strung together in a loose 3D web of six- and seven-membered rings.
Q 15Q-carbon, announced in 2015 by a North Carolina State University team, was made how?
By firing a laser pulse at amorphous soot
It reportedly shows ferromagnetism, fluorescence and hardness greater than diamond.
Q 16Linear acetylenic carbon, or carbyne, has a Young's modulus roughly how many times that of diamond?
40
It is a polymer of alternating single and triple bonds, of great interest to nanotechnologists.
Q 17What is the half-life of carbon-14?
About 5,700 years
That is why it is virtually absent from ancient rocks and useful for dating things only up to about 40,000 years old.
Q 18How is carbon-14 created?
Cosmic rays hitting nitrogen in the upper atmosphere
Thermal neutrons collide with nitrogen-14 nuclei at altitudes of 9 to 15 km, producing carbon-14 and a proton.
Q 19In what year was radiocarbon dating invented?
1949
It works because carbon-14 in a body stays roughly constant in life and then declines predictably after death.
Q 20What percentage of the carbon on Earth is the isotope carbon-12?
About 98.9%
Almost all the rest is carbon-13, the isotope chemists use for NMR; living things skew even further toward carbon-12.
Q 24Carbon has the highest sublimation point of any element. Roughly what is it at atmospheric pressure?
About 3,900 K
It has no melting point at normal pressure at all; its triple point is at about 10.8 MPa and 4,600 K.
Q 25What colour does diatomic carbon gas (C2) glow when excited?
Green
That green glow is what you see in the heads of comets and in a hot flame's inner cone.
Q 26Roughly how many carbon compounds have been described and indexed?
About 200 million
That is still only a fraction of what is theoretically possible; more known compounds contain carbon than do not.
Q 27Carbon's ability to form long chains of carbon-carbon bonds is called what?
Catenation
It is the reason organic chemistry is effectively boundless.
Q 28Which chemist showed in 1772 that diamond is carbon by burning it and finding it gave off the same gas as charcoal?
Antoine Lavoisier
He later listed carbon as an element in his 1789 textbook.
Q 29Before Scheele's work in 1779, graphite had been widely thought to be a form of which metal?
Lead
That confusion is why we still call pencil graphite 'lead'; Scheele showed it was charcoal with a little iron mixed in.
Q 30Who demonstrated in 1722 that iron becomes steel by absorbing some substance, later identified as carbon?
René Antoine Ferchault de Réaumur
Réaumur is better known for his thermometer scale.