The United Nations declared 2019 as the International Year of the Periodic Table of Chemical Elements to emphasize its first publication in 1869. The periodic table, as we know it today, was first developed by the Russian scientist Dmitry Ivanovich Mendeleev.
The periodic table is not just a typical wall decoration in school classes in the natural sciences, it is also an exceptional tool for scientists to understand and even predict the properties of all elements.
The United Nations announcement will help raise the profile of how chemistry can provide solutions to global problems in agriculture, education, energy, and health.
This year marks the 150th anniversary of Mendeleev’s first publication on the periodic table. Since its inception, the periodic table has been at the center of many vivid discussions and is now regarded as "one of the most important and influential achievements in modern science, reflecting the essence of not only chemistry, but also physics, biology and other disciplines."
Mendeleev's genius is to recognize that at that time not all the elements were known, so he left gaps in the table for undiscovered elements. At that time, only 63 elements were identified. However, the properties of the five other elements (spaces, brilliantly added to fill the table) can already be determined using the table.
The periodic table has been in the spotlight for decades, but several other scientists tried to organize all the known elements before it. Back in 1789, Antoine Lavoisier created a list of 33 elements and tried to uncover the secrets of chemical elements and classify them by their properties.
Scientists, such as Alexander-Emile Beguier de Chancourtois, John Newlands and Julius Lothar Meyer, proposed their own method of ordering the elements. A spiral, a chart, a cylinder, and even a spiral were proposed to visualize the arrangement of elements, but none of them fit perfectly.
Save some space
The discovery of some of these elements in subsequent years confirmed the predictions of Mendeleev and revealed the brilliance of the Periodic Law, as Mendeleev called his table.
After the first Mendeleev scheme, fifty-five elements were discovered, and all of them were included in the existing classification in accordance with their atomic mass. Of course, they have the properties provided by the incomplete table, which explains why Mendeleev’s attempt to streamline the elements was so successful and has survived the centuries.
Element 101 was named mendelevium in honor of Mendeleev's contribution. This is in fact an even rarer difference than receiving the Nobel Prize: only 50 scientists have elements named after them, and 180 chemists received the Nobel Prize in Chemistry.
In 2016, four more items were to be discovered in accordance with the gaps in the periodic table. With the addition of nionium, Muscovy, tennesin and oganesson, the periodic table is complete.
Or is it?
The proclamation of 2019 as the International Year of the Periodic Table can draw public attention to the importance of chemistry in our lives, arouse our curiosity to science and stimulate the interest of scientists to discover even more elements.
Alexandra Gelle, Ph.D., McGill University, Canadian Press
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