History of the periodic table

The periodic table contains all the elements that we know exist in the universe. It classifies elements into categories and makes predictions about elements that have not yet been found by humans. Let's take a look at some key milestones that led to it coming to its current form.

From alchemical table to periodic table

Long before the periodic table, the term "elements" referred to earth, air, water, and fire. At the time of ancient Greek philosophy (5th century BCE), the understanding of the chemical elements was represented by the alchemical table. This also ordered elements and substances and their corresponding symbols.

As more elements were discovered and a modern understanding of chemistry emerged, some components were removed from the table and others were added. Hennig Brand is the first person credited with discovering a modern element, phosphorus. Brand was an alchemist searching for the philosopher's stone. He distilled many substances including human urine, from which he obtained pure phosphorus.

Adding oxygen to the mix

Many consider Antoine Lavoisier the father of modern chemistry. His work was groundbreaking and instrumental to the current understanding of chemistry. Lavoisier discovered oxygen and hydrogen, and correctly explained the role of oxygen in combustion. He also predicted the existence of silicon. Many people built on the work of Lavoisier, contributing to the periodic table and its elements.

Organising the elements

In 1869, a Russian scientist named Dmitri Mendeleev organised the elements into the table structure we know today. He arranged the elements by atomic mass, starting with the lightest elements. By grouping elements into columns, he was able to correctly predict elements that had not yet been discovered. Mendeleev also knew that the proposed atomic masses of some elements were incorrect, and used his periodic table to correctly predict the actual masses.

The development of periodic law

Grouping the elements by atomic mass also led to Mendeleev discovering the periodic law. This law states that by grouping elements by atomic mass, we see trends in their properties. Periodic law has since been used to reliably predict the properties of elements.