(Roughly) Daily

Posts Tagged ‘Elements

“Taxonomy is described sometimes as a science and sometimes as an art, but really it’s a battleground”*…

The periodic table of elements, in the form introduced by Dmitri Mendeleev, is something that many of us take for granted. But as Philip Ball explains, there are a number of different visualizations making claims for our attention…

The Periodic Table was conceived as a scheme for bringing order to the elements. When there were deemed to be only four of these—the earth, air, fire, and water of the Greek philosopher Empedocles (it was just one of the elemental systems proposed in ancient times, but enjoyed the weighty advocacy of Plato and Aristotle)—things seemed simple enough. But during the Renaissance, natural philosophers were increasingly forced to accept that the metals then known—copper, iron, lead, tin, mercury, silver and gold—were not as interconvertible as the alchemists believed, but seemed to have an elemental primacy about them, too. More and more of these became recognized—zinc, bismuth, cobalt, and others—along with other new elements such as sulfur, phosphorus, carbon, and, in the late eighteenth century, gaseous elements like nitrogen, hydrogen and oxygen. When the French chemist Antoine Lavoisier (who named those latter two) drew up a list of known elements for his seminal textbook Traité élémentaire de chemie in 1789, he counted 33—including light and heat, which he called caloric.

The list didn’t seem to be arbitrary though. In the early nineteenth century, several scientists noted that some elements seemed to come in families, resembling one another in the kinds of reactions they engaged in and the compounds they formed. Some claimed to see triads: the halogens chlorine, bromine and iodine for example, or the reactive metals sodium, potassium (both discovered by English chemist Humphry Davy in 1807) and lithium (identified in 1817). Was there a hidden pattern to the elements?

The Russian chemist Dmitri Mendeleev, working at Saint Petersburg University, is usually credited with discovering that pattern. A Siberian by birth, with Rasputin-like dishevelled hair and an irascible manner, he published his first Periodic Table in 1869. It is “periodic” because, if you list the elements in order of their mass, certain chemical properties seem to recur periodically along the list. The table is produced by folding that linear list so that elements with shared properties sit in vertical columns (although Mendeleev’s first table had them instead in rows, effectively turning today’s table on its side)…

Still, it’s a weird kind of periodicity. At first, chemical properties seemed to recur every eight elements. But in the row that starts with potassium, there’s an interlude of ten metals—the transition metals—and so it continues thereafter, creating a periodicity of 18. And after lanthanum (element 57), chemists discovered a whole series of 14 metallic elements with almost identical properties that have to be squeezed in too—frankly, these elements, called the lanthanides after the first of their ilk, all seem a bit redundant. There’s another block like this after radioactive actinium (element 89), called the actinides. In most Periodic Tables, the lanthanide and actinide blocks are left floating freely underneath so the table doesn’t get stretched beyond the confines of the page. (Some insist that this long-form table is the only proper one.) Why this odd structure?

The answer became clear with the invention of quantum mechanics in the early twentieth century. The chemical properties of New Zealander Ernest Rutherford showed that atoms comprise a central, very dense nucleus with a positive electrical charge, surrounded by enough negatively charged electrons to perfectly balance that charge. Rutherford imagined the electrons orbiting the nucleus like moons, but in the quantum-mechanical description they occupy nebulous, smeared-out clouds called orbitals. Using quantum mechanics to describe the disposition of electrons shows that they are arrayed in shells. The first of these can contain just two electrons—this is the only shell possessed by hydrogen and helium, the two lone elements at the tops of the towers—while the next has eight, and then 18. The shape of the periodic table thus encodes the character of the quantum atom.

All clear? Not quite. Even now, there’s no consensus about how to draw the Periodic Table…

Read on to explore some fascinating alternative depictions: “Picture This: The Periodic Table,” by @philipcball in @PioneerWorks_.

* Bill Bryson, A Short History of Nearly Everything


As we ruminate on relationships, we might spare a thought for Vladimir Vernadsky; he died on this date in 1945. A Ukrainian mineralogist and geochemist, he is considered one of the founders of geochemistry, biogeochemistry, and radiogeology. He also co-founded and served as the first President of the Ukrainian Academy of Sciences (now National Academy of Sciences of Ukraine).

Vernadsky is probably best remembered for his 1926 book Biosphere, in which he popularized the concepts of the biosphere and the noosphere, arguing (after Eduard Suess) that in the Earth’s development, the noosphere (cognitive life) is the third stage in the earth’s development, after the geosphere (inanimate matter) and the biosphere (biological life). Just as the emergence of life fundamentally transformed the geosphere, the emergence of human cognition will fundamentally transform the biosphere. In this theory, the principles of both life and cognition are essential features of the Earth’s evolution, and must have been implicit in the earth all along (a position Vernadsky held was complementary to Darwin’s theory of evolution). Indeed, within the last 200 years, humanity has been a powerful geologic force, moving more mass upon the earth than has the biosphere.


Written by (Roughly) Daily

January 6, 2023 at 1:00 am

“Those distinct substances, which concretes generally either afford, or are made up of, may, without very much inconvenience, be called the elements or principles of them”*…

An interactive encomium to the elements…

A review of the Periodic Table composed of 119 science haiku, one for each element, plus a closing haiku for element 119 (not yet synthesized). The haiku encompass astronomy, biology, chemistry, history, physics, and a bit of whimsical flair…

Elemental haiku,” by Mary Soon Lee (@MarySoonLee) in @ScienceMagazine from @aaas.

Robert Boyle, The Sceptical Chymist


As we celebrate chemical compliments, we might send illustratively-arranged birthday greetings to Alexandre-Émile Béguyer de Chancourtois; he was born on this date in 1820. A geologist and mineralogist, he was the first to arrange the chemical elements in order of atomic weights (in 1862). But De Chancourtois only published his paper, not his graph with the novel arrangement; and because it was a geology paper, it was largely ignored by chemists. It was Dmitri Mendeleev’s table, published in 1869, that became the standard– and the model for the periodic table that we know today.


“The laws of nature are but the mathematical thoughts of God”*…



2,300 years ago, Euclid of Alexandria sat with a reed pen–a humble, sliced stalk of grass–and wrote down the foundational laws that we’ve come to call geometry. Now his beautiful work is available for the first time as an interactive website.

Euclid’s Elements was first published in 300 B.C. as a compilation of the foundational geometrical proofs established by the ancient Greek. It became the world’s oldest, continuously used mathematical textbook. Then in 1847, mathematician Oliver Byrne rereleased the text with a new, watershed use of graphics. While Euclid’s version had basic sketches, Byrne reimagined the proofs in a modernist, graphic language based upon the three primary colors to keep it all straight. Byrne’s use of color made his book expensive to reproduce and therefore scarce, but Byrne’s edition has been recognized as an important piece of data visualization history all the same…

Explore elemental beauty at “A masterpiece of ancient data viz, reinvented as a gorgeous website.”

* Euclid, Elements


As we appreciate the angles, we might spare a thought for Kurt Friedrich Gödel; he died on this date in 1978.  A  logician, mathematician, and philosopher, he is considered (along with Aristotle, Alfred Tarski— whose birthday this also is– and Gottlob Frege) to be one of the most important logicians in history.  Gödel had an immense impact upon scientific and philosophical thinking in the 20th century.  He is, perhaps, best remembered for his Incompleteness Theorems, which led to (among other important results) Alan Turing’s insights into computational theory.

Kurt Gödel’s achievement in modern logic is singular and monumental – indeed it is more than a monument, it is a landmark which will remain visible far in space and time. … The subject of logic has certainly completely changed its nature and possibilities with Gödel’s achievement.                  — John von Neumann

kurt_gödel source


Written by (Roughly) Daily

January 14, 2019 at 1:01 am

%d bloggers like this: