Celebration of the Periodic Table

The periodic table of chem ical elements is one of the most significant achieve ments in science because it arranges the 118 known ele ments in a deceptively simple pattern that reveals their properties. So how did this “Rosetta Stone of Nature” originate? Most likely, you will answer Dmitri Mendeleev, the Russian chemist who in 1869 published a version of the periodic table that we recognize today. His table expresses the periodic law: elements arranged according to the size of their atomic weights show periodic properties. To celebrate the 150thanniversary of this great achievement, the United Nations and UNESCO declared 2019 to be the International Year of the Periodic Table of Elements. But does Mendeleev deserve all the credit? Scientific discoveries rarely arise in isola tion; rather contributions from researchers over many years lead to a general picture that eventu ally emerges. But, sometimes, scientific discov eries are made simultaneously by different researchers. Such is the story of the periodic table.