The chemical elements are arranged in a periodic table according to their atomic weights, electron configurations, and chemical characteristics. Since it was initially conceived, the periodic table has undergone many changes and improvements.
Early 19th-century Russian chemist Dmitri Mendeleev grouped the known elements in a table according to their atomic weights and chemical characteristics, which is when the periodic table idea first emerged. In addition, Mendeleev's table featured spaces for elements that weren't yet known, and he could forecast the properties of these undiscovered elements based on where they were located in the table.
Following Mendeleev, several researchers created their own periodic tables, notably Julius Lothar Meyer and William Odling. The links between the elements were made more explicit and more precise in 1913 when Henry Moseley created a periodic table based on the atomic number of the elements rather than their atomic weights.
The periodic table has undergone many alterations and refinements since the early twentieth century as new elements have been discovered and new techniques for researching the elements have been developed. The present periodic table contains 118 elements grouped into 18 groups and 7 periods.
Since 2021, several new elements have been discovered or synthesized, and these elements have been added to the periodic table.
Element 117, now known as tennessine, was introduced to the periodic table in 2012 after being synthesised by a team of researchers from the United States and Russia.
Element 118, now known as oganesson, was also added to the periodic table in 2016 after being synthesised by a collaboration of Russian and American scientists.
One little-known fact about the periodic table is that the original periodic table was published in 1869 by Dmitri Mendeleev, before many of the elements it contained had even been discovered.
Mendeleev left gaps in his table for elements he believed will be discovered in the future, and many of his forecasts proved correct when the elements were discovered.
Another interesting fact about the periodic table is that when it was first proposed, it was not instantly embraced by the scientific community. On the contrary, many scientists met Mendeleev's periodic table with skepticism, and it took several years for it to acquire universal recognition. Finally, since its inception, the periodic table has experienced numerous revisions and adjustments. As our grasp of the underlying science has increased, new elements have been found, and the ways in which the elements are ordered and classed have changed.
The most recently found element was oganesson (element 118), which was synthesised in 2002 by a collaboration of Russian and American scientists. Oganesson is a highly radioactive synthetic element that belongs to the periodic table's noble gas category. It is one of the heaviest elements known, and it is so unstable that it decays nearly instantly into other elements.
In 2016, the International Union of Pure and Applied Chemistry (IUPAC) formally acknowledged oganesson as a new element, and it was added to the periodic chart. It is the most recently discovered element, however, research into the possibility of synthesising much heavier elements is ongoing.
However, these efforts are still in the early stages, and it is not yet known if it will be possible to create elements heavier than oganesson.