Capturing Carbon Trivia Quiz

Answer: It depends on the circumstances

Depending on the circumstances in which pure carbon is formed, it can take all of these appearances and more.

Amorphous carbon is a black powder, in which the carbon atoms are scattered all over the place. It is one of the main ingredients of soot, for instance. Occasionally, it could form lumps, but this is not because of the cohesion of the carbon atoms, but of the other elements in the soot.

At normal pressure and temperature, pure carbon can organise itself into greyish flakes of graphite: the carbon atoms link together into planar hexagons, which give great strength in the horizontal plane but no coherence with the upper and lower layers. That's why graphite is used for pencils: the flakes let loose easily, and each flake leaves a trace on the paper or wood you use your pencil on.

Under high pressure, pure carbon condenses to diamonds: transparent solids with a crystalline structure. Diamonds are the hardest objects on earth.

Pure carbon can also appear as a liquid or a gas (at high temperatures and normal to very low pressure).

Answer: Ethylene dione (C2O2)

Carbon monoxide is the byproduct of incomplete combustion and is toxic in high concentrations.

Plants use carbon dioxide and water to form nutrients with the help of sunlight (photosynthesis), and they expel oxygen. In turn, animals inhale oxygen and exhale carbon dioxide.

Carbon suboxide (C3O2) is very rare. It was only detected for the first time in 1873, when a chemist sent an electrical current through an atmosphere saturated with carbon dioxide.

On the other hand, ethylene dione (C2O2) has not been observed yet. Theories about ethylene dione are that it is so unstable it would disintegrate only fractions of seconds after coming into being.

Answer: Cutting hard materials

As diamond is the hardest material on earth, it can grind and cut anything. So the saws and drills with highest demands are coated with grinded diamond powder.

Diamonds are poor electrical conductors (except for the quite rare blue diamonds, that contain boron inclusions which are responsible for this atypical property). So electricity via diamond is a no-go: the best electrical conductor is silver, and a cheaper alternative is copper.

Answer: False

Acids, in the chemical sense, all have pH values less than 7, while bases have a pH higher than 7. Chemical acids will tend to lose a proton (H+), while bases tend to accept protons.

Over 500 amino acids have been discovered in nature, and 20 of them have been the object of intense research, as they form proteins and encode genetic information. Glutamate (C5H7NO3) and aspartate (C4H5NO3) act as true acids, while arginine (C6H12N4O), lysine (C6H12N2O) and histidine (C6H7N3O) act as bases.

Answer: Sugars

Carbohydrates in the most simple form are sugars: monosaccharides like glucose and fructose, both with the formula C6H12O6, or disaccharides such as sucrose (C12H22O11). But they also come in very long chains as amylose (part of starch), which concatenates 300 and more glucose molecules.

Acids in the chemical sense are ionic compounds that can either "give away" a hydrogen proton H+ (thus resulting in a negative electric charge), or form bonds with a pair of electrons. Acids react readily with (metallic) bases. A well-known example is citric acid, with the formula C6H8O7.

Salts in the chemical sense are the result of a reaction between an acid and a base, and thus are usually electrically neutral. Common table salt, with the formula NaCl, is a fine example.

Chemistry does not recognize bitters as a type of molecule. Bitters are mixtures of water and alcohol in which herbs, roots, barks, fruits and/or spices are dissolved, and they are used as an ingredient in cocktails or as an aperitif or digestive.

Answer: Ethanol

Ethanol is the carbohydrate ethylene chemically bound to a hydroxyl group and has the formula C2H5OH (alternately also written down as CH3CH2OH or C2H6O). In nature, ethanol is created by the fermentation of sugars. While chemists use the official name ethanol, many non-chemists call this substance merely alcohol. Ethanol is present in beers, wines and spirits, and is known for calming down the nervous system. (Hence the expression "I need to calm down - give me a stiff drink"). However, it has a number of side effects, from impairing the decision making process (very dangerous when one drives a vehicle or operates a heavy machine), over addiction to causing serious diseases as cancer or liver cirrhosis.

Methanol (CH3OH) is the simplest molecule in the alcohol category. It is highly flammable and very toxic, causing irreparable damage to the optic nerve.

Sorbitol has the formula C6H8(OH)6 or, alternatively, C6H14O6. In chemistry it is a more complex alcohol (multiple hydroxyl groups). Sorbitol is used as a sweetener, but can also have laxative effects.

Menthol has the formula C10H19OH or the shorter C10H20O. It is found naturally in small doses in various mint plants.

Answer: As a soccer ball

C-60 is the chemical formula for a molecule consisting of 60 carbon atoms, and nothing else. This molecule is also known as buckminsterfullerene, named after the American architect Richard Buckminster Fuller who built several domes in a shape that resembles half a C-60 fullerene.

The shape of a C-60 fullerene is that of a soccer ball: a sphere constituted of 12 pentagons and 30 hexagons, where none of the pentagons touch each other. Each of the 60 carbon atoms is linked to three other carbon atoms, while the fourth valence is free - the fullerene is thus unsaturated.
Chemists at Rice University discovered C-60 and C-70 fullerenes in 1985, but since then several others have been demonstrated - from C-20 up to C-100.

The pipeline shape corresponds with the carbon nanotubes, a series of molecules of pure carbon that is typically a series of hexagons wrapped around an open cylinder. Nanotubes usually have open ends, whereas the spherical fullerenes (in popular magazines also known as "buckyballs") are totally closed.

The dumbbell shape could theoretically exist if each open end of a carbon nanotube is linked to a closed fullerene. I've found no evidence that this shape has been discovered at the time of writing this quiz.

The question mark is, of course, a pure figment of my wild imagination.

Answer: Coating for cutting tools

Both titanium carbide (TiC) and tungsten carbide (WC) are extremely hard materials that maintain their hardness at elevated temperatures. That's why they are frequently used to coat the blades of cutting tools such as saws, knifes, chisels or drill bits.

Ceramic plates for bulletproof vests also use carbides, but most often boron carbide or silicon carbide. These ceramic plates give adequate protection and are lightweight applications, but their drawback is an inferior protection against multiple hits.

Calcium cyanamide has the chemical formula CaCN2. It contains no trace of titanium or tungsten, and is mostly prepared with calcium carbide.

Desalination is either by distillation (in which no chemical compounds are used) or by osmosis, which needs only a polyamide layer as a filter.

Answer: False

Polymers have been studied from 1830 onwards, but they were already used frequently since very old times. Cellulose with the chemical formula (C6H10O5)n, (in which n can reach into the range of 1000 odd), has been used for millennia to create paper. Shellac (C30H50O11) has been used for centuries as a coating. Wool and hemp are also biopolymers.

Synthetic polymers can have various applications: clothing (nylon), food packaging (polyethylene terephthalate), protection (Kevlar) and non-stick pans (Teflon) among them.

Answer: Cyanide

Cyanides are the compounds to answer this question. Potassium cyanide, found in the seeds of almonds, apples and peaches, is the best known for its toxicity. The most common use of potassium cyanide and the very similar sodium cyanide is in mining precious metals, although several countries have banned the use of cyanides for this purpose.

Potassium bitartrate (KC4H5O6) is also known as "cream of tartar", one of the ingredients in the mixture baking powder.

Nitrates and chlorides don't necessarily include carbon atoms.
Potassium nitrate (KNO3) is not toxic. It is used as a fertilizer and as part of gunpowder while
potassium chloride (KCl) is a salt compound akin to (but not as strong in taste) sodium chloride (NaCl).