Issa Yavari - Department of Chemistry, Tarbiat Modares University, Tehran, Iran

In chemistry, the Periodic Table of Elements is the map that outlines an ordered system of all the identified elements that make up everything in our universe. The chemical elements that make up the periodic table are the building blocks for water, plants, minerals and everything in nature. These elements also create the products and technologies that have shaped modern societies in countless ways – clean drinking water, effective medicines and technologies ranging from solar panels to electronics components, all rely on chemistry.The Periodic Table represents more than 5,000 years of human discovery. The United Nations has declared 2019 the “International Year of the Periodic Table of the Chemical Elements,” to celebrate the 150th anniversary of the first periodic table and recognize the important role chemistry plays today in promoting sustainable development and providing solutions to global challenges. Academic institutions, chemistry societies and industry will all be celebrating the periodic table throughout 2019. But you don’t have to be a chemist or scientist to appreciate the periodic table.In 1869, Russian chemist Dimitri Mendeleev wanted to see if there was a pattern to the chemical properties of the elements he knew. He found one by listing elements by their increasing atomic number and arranging them in a chart – creating the first periodic table. This structured order helped Mendeleev, and other scientists, identify similarities and differences among elements to help predict future chemical reactions. While Mendeleev’s periodic table included 63 elements, he anticipated that others would one day be discovered, so he left open spaces in his table for additions. Today, the 118 chemical elements identified on the periodic table include the materials that make up all known objects in the universe.

Periodic table, Chemical elements, Periodic law