150 Years of the Periodic Table

2019 marks the 150th anniversary of the creation of the periodic table, and it has been declared the International Year of the Periodic Table by the United Nations Educational, Scientific, and Cultural Organization (UNESCO).

Here, we take a look at the fascinating history of the people behind the table, starting in 450 BCE and going through the present day, and the way the table and understanding of elements has evolved over time. Even today, many aspects of the periodic table remain unresolved—including a consensus on just how many elements remain undiscovered, leaving much room for discovery and further development in the future.

Featured age credit: “Beaker glass ware” by uncredited. Public Domain via Pxhere.