Every few decades, the periodic table — that familiar grid of squares hanging in every chemistry classroom — gets a little bit bigger. In January 2016, it gained four new occupants at once: elements 113, 115, 117, and 118.
The International Union of Pure and Applied Chemistry (IUPAC), the global authority on chemical nomenclature, officially confirmed all four elements, completing the seventh row of the periodic table for the first time in history.
Who Discovered Them?
The discoveries came from research teams across three countries:
- Element 113 was discovered by a team at RIKEN Nishina Center for Accelerator-Based Science in Japan — making it the first element on the periodic table to be discovered in Asia. The Japanese team spent over a decade working toward this confirmation.
- Elements 115 and 117 were credited to a collaboration between the Joint Institute for Nuclear Research in Dubna, Russia, and the Lawrence Livermore National Laboratory in California, USA.
- Element 118 was also a joint Russian-American discovery, from the same Dubna-Livermore collaboration.
What Are They?
All four are superheavy elements — synthetic elements that don't exist in nature and can only be created in particle accelerators by smashing lighter atomic nuclei together at high speed. They're extraordinarily unstable, existing for only fractions of a second before decaying into lighter elements.
At the time of the announcement, the elements still had temporary names based on their atomic numbers (ununtrium, ununpentium, ununseptium, and ununoctium). IUPAC later assigned them their official names:
- Element 113: Nihonium (Nh) — named after Japan (Nihon)
- Element 115: Moscovium (Mc) — named after Moscow
- Element 117: Tennessine (Ts) — named after Tennessee
- Element 118: Oganesson (Og) — named after physicist Yuri Oganessian
Why Does It Matter?
At first glance, superheavy synthetic elements that last milliseconds seem like pure laboratory curiosities. And to some extent, they are — practical applications for elements this unstable are essentially non-existent. But the research matters for deeper reasons.
Understanding how atomic nuclei behave at the extremes of the periodic table tests our fundamental models of nuclear physics. Theoretical physicists have long predicted the existence of an "island of stability" — a region of the periodic table where certain superheavy elements might be substantially longer-lived than their neighbors. Each new superheavy element discovered brings researchers closer to understanding whether that island really exists and where it might be found.
For now, the periodic table sits complete through element 118. Work on elements 119 and 120 is already underway in multiple laboratories worldwide.
Source: IUPAC – International Union of Pure and Applied Chemistry
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