2019 Is The Year Of The Periodic Table of Chemical Elements

Jessica Clifton

by Jessica Clifton

18th September 2019

The United Nations General Assembly has officially designated 2019 as the International Year of the Periodic Table of Chemical Elements

One of the most critical and significant achievements in science, the periodic table gives structure and a common language to science. It has become an iconic image as well as an important tool for everyone learning about science and everyone working in science disciplines.

The International Year of the Periodic Table not only recognises its importance as one of the most influential achievements in modern science, including not only chemistry but also physics, biology, and other scientific disciplines, but also celebrates the 150th anniversary of the creation of the first periodic table in 1869 by Russian scientist Dmitri Mendeleev.

What is the Periodic Table?

The periodic table displays all the chemical elements we know about in a table. This table is arranged by atomic number, electron configuration, and recurring chemical properties. 


The periodic table of chemical elements

The seven rows of the table, the ‘periods’, mostly contain metals to the left and non-metals to the right. The columns, or ‘groups’, have elements with similar chemical behaviours. Check out this amazing interactive periodic table and explore the different chemical elements. 

What is the Periodic Table Used For?

The periodic table of chemical elements is a unique tool that allows scientists to predict the appearance and properties of matter, both on earth and in the wider universe. It is also used to predict the properties of new synthetic elements before they are produced and studied.

The History of the Periodic Table

Before the periodic table could even be thought of, we had to discover individual chemical elements. Metal elements like gold, silver, copper, lead, and mercury have been used for thousands of years, but it wasn’t until 1649 that the first scientific discovery of an element was made when Hennig Brand discovered phosphorous. Over the next 150 years, more and more chemical elements were discovered and chemists built up a store of knowledge about their different properties. 

The periodic table of chemical elements is one of the most significant achievements in science

In 1789, French chemist Antoine Lavoisier published a list of 33 chemical elements, grouped into gases, metals, nonmetals, and earths. From this starting point, scientists spent the best part of the following 100 years trying to perfect Lavoisier’s classification scheme and discover more elements.

By 1869, a total of 63 elements had been discovered, and it was in this year that Dmitri Mendeleev published his first periodic table. This first table was constructed by listing the chemical elements in rows or columns in order of atomic weight. A new row or column started when the characteristics of the elements began to repeat and there were gaps where Mendeleev predicted there should be an element that had not yet been discovered.

When Ernest Rutherford, the “father of nuclear physics”, discovered the atomic nucleus in 1911, it changed the periodic table. The atomic number became the absolute definition of an element and provided a firm basis for the arrangement of the periodic table. 

The periodic table as we know it today was created by American chemist Horace Groves Deming in 1923. By the 1930s Deming’s table could be found in textbooks, handbooks, and encyclopedias of chemistry – where it can still be found to this day.

The Periodic Table in 2019

The periodic table is still growing as we discover more elements. While there were just 63 chemical elements in 1869 when Mendeleev first created the periodic table, there are now 118 elements. 

The most recent new element to be added to the periodic table is tennessine (element 117). Discovered by a Russian/U.S. collaboration, it became an official chemical element on 28 November 2016.


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