The History of the Periodic Table

Author: William Tsay

Editors: Jasleen Matharu and He-Hanson Xuan

Artist: Jennifer Hu

The Periodic Table of Elements is ubiquitous in science classrooms and has become an icon of chemistry. It contains 118 known elements and their chemical symbols, atomic numbers, and atomic masses but is continuously advancing as scientists discover new elements. However, the arrangement of the periodic table was determined more than a century ago, before the discovery of all current known elements. How did scientists invent this complex table before they discovered all present-day elements, and can we see any patterns?

In 1860, the International Conference on Chemistry of Germany published a list of elements and their ato