Setting the
Table

This visualization offers a brief history of the periodic table. For convenience, elements are represented throughout by their abbreviations, even before those abbreviations were conceived. In many ways, the history of the table tracks the modern development of chemistry as a science.

You can hover over each element for its name.

Several of the elements in the periodic table have been known in (mostly) pure form since ancient times. The Iron Age, for instance, ensued from the fundamentally chemical discovery that metallic iron could be recovered from its ore by heating with carbon.

As history progressed, more elements were isolated throughout the world, though the idea that these were the fundamental “elements” underlying all other substances was not yet clearly understood.

1669 Hennig Brand

In addition to the periodic table’s anniversary, 2019 marks the 350th anniversary of Hennig Brand’s isolation of phosphorus, which he accomplished by concentrating urine.

1789 Antoine Lavoisier

The 1770s marked a turning point, when precise experiments led to isolation of gases such as oxygen and nitrogen and a unifying framework to explain their reactivity. Antoine Lavoisier and L. B. G. deMorveau compiled a “Table of Simple Substances,” published in 1789, that starts to look like a precursor of the periodic table (it was just one long column but has been broken in four here to fit the layout).

The elements were clustered in several groups (such as metals and non-metals) but weren’t otherwise well ordered. Light and heat were included but later jettisoned. F and B were only notional fragments of their acids, and the final five (Ca through Si) were not differentiated from their minerals.

1864 Julius Lothar Meyer

By the 1860s, a general consensus was reached on how to order the known elements by weight. Several chemists then recognized that certain properties, such as density or oxide stoichiometry, manifested a repeating pattern that lumped the elements into distinct mutually similar groups. Most prominent among these pioneers were Julius Lothar Meyer and Dmitri Mendeleev.

1869 Dmitri Mendeleev

Mendeleev’s seminal achievement was his prediction in 1869 of specific missing elements (with weights of 45, 68, and 70) on the basis of his periodic system.

The discovery within 17 years of gallium, scandium, and germanium—the properties of which all matched Mendeleev’s predictions—cemented his legacy as father of the periodic table.

1890s William Ramsay

As the nineteenth century drew to a close, the noble gases were discovered, primarily by William Ramsay and collaborators. Ramsay proposed to Mendeleev that he add them to the table as a new column.

1913 to 1925
Henry Moseley

The discovery of protons and elemental isotopes prompted Henry Moseley to champion a new ordering principle for the periodic table based on atomic number (i.e., number of protons) rather than atomic weight. Relatedly, Moseley’s x-ray emission studies provided a precise method for identifying each element.

A popular version of the updated table was published in a 1920s textbook by H. G. Deming (just before recognition of the last missing stable element, rhenium).

1955 Glenn Seaborg

The adventure remaining was synthesis of the short-lived radioactive elements, most of them heavier than actinium. This project proceeded throughout the rest of the 20th century and into the 21st. Glenn Seaborg, a pioneer and lifelong discoverer of unstable actinide elements, started placing them in their own row below the rare-earth elements. Element 101 was discovered in 1955 and named for Mendeleev. Seaborg was later honored with his own element, seaborgium.

The current layout of the periodic table was finally settled in 2016. Now, researchers around the world, including element 118’s namesake Yuri Oganessian, are working to push into an eighth row of the table. However, the challenges of discovering new elements grow with the number of protons. Some scientists think that the table’s periodicity could break down as atoms get larger. If that happens, the periodic table could need reshaping once more.