By Ron B. Davis Jr., Georgetown University
In recent times, the discovery and naming of elements have proven to be a contentious process. National and personal pride are often on the line. And there are many false steps along the way. In an attempt to harmonize the way that scientists talk and write about the elements, a new international organization called IUPAC was formed in 1919.
Classification of the Elements in Ancient Times
The ancient Greek philosopher Empedocles is generally credited with being the first to propose that four distinct elemental substances existed: earth, water, air, and fire. According to Empedocles, all other substances in our world were just varying combinations of these four elements.
Shortly after that, Aristotle attempted to classify each of these four classical elements using a matrix of two properties. Elements could be either wet or dry, and they could be hot or cold. The fire was hot and dry, while the air was hot and wet. Earth was cold and dry, while water was cold and wet.
These elements were often depicted in a square or diamond arrangement so that elements that shared one of these properties also shared a connection in the diagram. In this sense, Aristotle can be credited with producing the first table of elements.
In ancient China, a similar system had five elements: water, earth, fire, wood, and metal. In ancient India, a system of earth-water-fire sometimes included air as well as an element for ‘void’ or ’emptiness’.
Each of those ancient systems arranged their small list of attempted elements in a spatial arrangement to convey their properties.
This article comes directly from content in the video series Understanding the Periodic Table. Watch it now, on Wondrium.
Alchemist Symbols
Science is all about communicating, and chemistry is no exception. To document their ideas, the ancient alchemists of Greece, India, China, and other cultures devised ways to represent their elements using symbols.
Even at the start of the 19th century, the use of alchemist symbols to represent different elements was still commonplace. English chemist John Dalton is most famous for offering the first scientific evidence for atoms, but he did so by making use of symbols that were more reminiscent of those used by ancient alchemists.
However, a closer look at Dalton’s important textbook from 1808 also reveals that a change was taking place. Although his symbols for elements like hydrogen, carbon, and oxygen were still graphical in nature, reminiscent of alchemical symbols, other elements like iron, lead, and copper were represented using English letters.
Using Abbreviations
Just five years after Dalton’s book, Jons Jakob Berzelius compiled a table of relative atomic weights that introduced a system of elemental symbols based entirely on one- and two-letter abbreviations, many of which we still use today.
Today’s elemental symbols for elements discovered entirely in modern times tend to make sense: ‘N’ for nitrogen, and ‘Cl’ for chlorine, for example. But ten elements have symbols based on Greek or Latin words. 8 of those elements were known since ancient times, such as iron, whose symbol is ‘Fe’ for the Latin ferrum.
IUPAC and Naming of Elements
Since 1919, the International Union of Pure and Applied Chemistry, or IUPAC, has become the most influential global organization in chemistry—and for the periodic table in particular. Today when a scientist or group of scientists discovers or creates a new element, their work must be independently verified. Only then are they given the honor of proposing that new element’s name. But a discoverer can’t propose just any name. IUPAC recommends that an element’s name take its inspiration from one of five sources.
First, several elements discovered in the nineteenth century got their names from a mineral or other source material. Beryll-IUM was named for the mineral beryl. ‘Sod-IUM’ was named for soda. Second, elements can be named for a place. More than 25 elements have been named in honor of places, including Germanium, Francium, and Europium.
Third, elements can be named for a mythological figure: as is the case for titanium or promethium. Some element names of this type even manage to double-dip, like mercury, uranium, neptunium, and plutonium, since they are named for planets or other astronomical bodies (places), which themselves are named for mythological figures.
Fourth, elements can be named for a person. Beginning with curium in 1945, a total of 15 elements created in laboratories were named in honor of important scientists, including Einstein, Mendeleev, and even Copernicus.
Fifth, elements can be named for a property of the element—as has been done for some 50 elements on the table. Hydro-gen literally means ‘water generator’, an acknowledgment of the reaction that makes water when hydrogen combusts with oxygen.
‘UN-obtainium’ and IUPAC Rules
Now, why has no one yet chosen to name any of the more recently discovered elements ‘UN-obtainium’. This is a fictional element name, made famous by the popular film Avatar, and it’s in wide use as an imaginary element in science and engineering exams around the world.
Well, based on the IUPAC rules, the name ‘unobtainium’ presents two problems. First, its wide use in popular culture disqualifies the name, since it would likely cause confusion between the fictitious substance and the real element.
The second problem is that the IUPAC guidelines state that if a property is chosen as the inspiration for the name, it must be a property of that element. But here is the catch-22: the other IUPAC rule is that in order to name an element, one must first obtain it. So that means the name ‘obtanium’ is still available.
Common Questions about Discovering and Naming of Elements in Chemistry
The IUPAC, or the International Union of Pure and Applied Chemistry, was formed in 1919 to harmonize the way scientists write and talk about elements in chemistry. Since then it has become the most influential global organization in chemistry—and for the periodic table in particular.
To document their ideas, the ancient alchemists of Greece, India, China, and other cultures devised ways to represent their elements using symbols. Even at the start of the 19th century, the use of alchemist symbols to represent different elements was still commonplace.
The IUPAC recommends that one of the following five sources be used for the naming of elements: the elements can get their names from minerals; elements can be named for a place; elements can be named for a mythological figure; elements can be named for a person; and elements can be named based on their properties.
