The Element Carbon
Found in many forms, carbon is one of the most common elements in the universe. It is also one of the most important elements and forms the basis for all life as we know it! Find out more about this amazing element below.
A History of Carbon
Unlike most elements, humans have been aware of carbon since ancient times. As early as 3750 BC, ancient Egyptians and Sumerians used charcoal, a form of carbon, to reduce various metals in the manufacturing process. The use of carbon continued until 1789 when Antoine Lavoisier listed carbon as an element for the first time. Many other forms of carbon have been discovered such as diamonds, graphite, graphene, and fullerene. Fullerene even won a Nobel Prize in Chemistry in 1996 the prize went to Robert Curl, Sir Harold Kroto, and Richard Smalley. Carbon continues to be actively investigated and plays a vital role in all fields of chemistry.
Common allotropes of carbon
There are many different forms or allotropes of carbon. One of the most common of these is amorphous carbon which does not have a defined crystal structure. Coal is the most common example of amorphous carbon. Diamond is another well-known allotrope of carbon, with many uses, both industrial and cultural. The strong tetrahedral lattice of carbon-carbon bonds gives diamond its remarkable strength and characteristic shine. Pencils are an excellent example of another allotrope of carbon, graphite. Graphite consists of many large sheets of carbon sitting on top of each other. These sheets breaking off then is what enables you to leave marks on your paper with a pencil. There are also many other less common forms of carbon such as fullerenes and carbon nanotubes.
Interesting facts about Carbon
- Measuring amounts of the radioactive isotope Carbon-14 can help us to determine the age of things such as archaeological artifacts and ancient documents.
- Carbon nanotubes are one of the strongest materials in the world and have been proposed as a possible building material for some wild inventions such as a space elevator.
- All life as we know it is based on carbon.
- Over 10 million compounds that we know of so far can be formed by carbon, more than any other element.
- Carbon is the 4th most abundant element in the universe but only the 15th most abundant element in the earth’s crust.
- All other elements’ atomic weights are measured relative to carbon-12.
Common reactions and synthesis
Carbon is used in numerous reactions in all branches of chemistry. One of the most common is combustion reactions, where a hydrocarbon reacts with oxygen to form carbon dioxide and water. Another important reaction with carbon is ocean acidification. This is when carbon dioxide dissolves in the ocean and reacts to form carboxylic acids, lowering the pH of the ocean. Carbon generally does not require significant effort to isolate. Coal, diamond, and graphite, are all pure, naturally occurring forms of carbon.
Carbon can make a wide variety of different compounds. Two significant ones are carbon monoxide and methane. Methane has one of the highest per molecule warming potentials out of all the greenhouse gases. Carbon monoxide is a colorless odorless gas that can be fatal to humans. However, carbon monoxide can also serve as a useful ligand for many inorganic reactions. Another category of interesting carbon compounds is pi-conjugated systems. The overlap of several pi orbitals to create a delocalized system of electrons is called a pi-conjugated system. The vivid colors that are formed make these compounds especially useful and pretty to look at.
Carbon in organic chemistry
Organic chemistry is one of the largest subfields in chemistry and is based entirely on carbon! Carbon can form very strong bonds with other carbon atoms, making it one of the building blocks for most organic compounds. Carbon is also able to form bonds with many other elements such as oxygen, nitrogen, and hydrogen. The bonds formed between carbon and these elements form the basis for functional groups, which enable the creation of a wide range of compounds from pharmaceuticals to dyes!
Carbon and the climate
Levels of carbon in the atmosphere in the form of carbon dioxide have been rising steadily since the industrial revolution. This has been accelerating greatly in the last few decades and has led to drastic changes to the climate and a general increase in temperatures. This is because of the greenhouse effect, where the heightened levels of carbon dioxide in the atmosphere trap incoming sunlight and the earth warms as a result.
Although the earth has some natural carbon sinks, such as dissolved CO2 in the ocean and organic plant matter, these sinks have not been able to keep up with the increased levels of carbon as a result of human activity. There is a great deal of active research investigating ways to mitigate and reverse this trend. This encompasses a wide variety of different areas. For instance, carbon capture technology is a way to possibly remove carbon dioxide from the atmosphere. Ways of generating energy without generating carbon, like wind and solar, is another area of active research.
Carbon and polymers
The strong bonds between carbons also enable the formation of polymers, long chains of linked carbon atoms. An important subcategory of polymers is plastic, one of the most common materials in our lives. The strength and versatility of carbon-carbon bonds enable polymers and plastics to serve many functions. Everything from durable water bottles to airplanes uses plastic in their construction. But these strong bonds can also make it hard to break down these materials, and many things made of plastic never break down and end up causing pollution and damage when they make their way into the environment.
Advances are also being made in this field, and a new enzyme was just created that can break down plastics naturally. This provides a possible new avenue for recycling carbon-based plastics instead of incineration or putting them into a landfill.
Learn more about other elements!