The International Union of Pure and Applied Chemistry (IUPAC) on 30 December 2015 announced discovery and assignment of elements with atomic numbers 113, 115, 117 and 118.
The decision was taken by the IUPAC as the four elements met the discovery of elements of the IUPAP/IUPAC Transfermium Working Group (TWG) 1991 Discovery Criteria.
All these four elements are synthetic in nature. They were discovered by scientists belonging to the USA, Russian and Japan and complete the 7th row of the periodic table of the elements.
Also, these four elements are the first to be added to the table since 2011, when elements 114 (Flerovium, FI) and 116 (Livermorium, LV) were added.
Naming of elements: After officially recognizing the elements, the IUPAC also invited suggestions related to permanent names and symbols from the scientists who discovered them.
New elements can be named after a mythological concept, a mineral, a place or country, a property or a scientist.
Details of four elements
• Temporary working name and symbol are ununtrium and Uut respectively.
• It was discovered by the scientists belonging to RIKEN research laboratory in Japan.
Elements 115 & 117
• 115: ununpentium, Uup are the temporary working name and symbol respectively.
• 117: ununseptium, Uus are the temporary working name and symbol respectively.
• In discovering the element 117 Indian scientist Susanta Lahiri played an important role.
• They were discovered by scientists belonging to Russia and the USA in collaboration
• It has ununoctium and Uuo as the temporary working name and symbol respectively.
• It was jointly discovered by scientists belonging to the Nuclear Research in Dubna, Russia and Lawrence Livermore National Laboratory, California, USA.
How they were discovered?
They were discovered by slamming lighter nuclei into each other and tracking the following decay of the radioactive superheavy elements.
Like other superheavy elements that populate the end of the periodic table, they only exist for fractions of a second before decaying into other elements.
• It is an association of bodies, National Adhering Organizations, which represent the chemists of different member countries.
• It was formed in 1919 by chemists from industry and academia and headquartered in Zurich, Switzerland.
• It serves to advance the worldwide aspects of the chemical sciences and to contribute to the application of chemistry in the service of mankind.
• Over nearly eight decades, it has succeeded in fostering worldwide communications in the chemical sciences and in uniting academic, industrial and public sector chemistry in a common language.
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When: 30 December 2015