Dmitri Mendeleev flipped through “Principles of Chemistry” anxiously looking for the next assignment to give to his class. After scanning a few more pages he slammed the book shut, rushing to work on his next task: A way to organize the elements.
Mendeleev pulled out his notebook and a pile of papers he had been studying and turned to the page he had left off on. His first document to view was John Newlands “Laws of Octaves” in which John Newlands explained how the 56 elements that had been discovered so for were organized into eleven groups by physical properties. He had also pointed out that similar elements existed in multiples of 8 in atomic number.
Making a mental note of this, Mendeleev opened his notebook, which contained a list of elements and their properties. After looking at the page for what seemed like hours, he finally drew a table, and began to organize the elements by their chemical properties, rather than their physical properties. Mendeleev began to notice patterns and excitedly began to take notes. He noticed that if the elements were organized by their atomic weight they show periodicity properties and that the elements with similar chemical properties have atomic weights that are nearly the same. He also noticed that their atomic weight corresponds with their valencies and that the atomic weight somewhat determined the character of the element.
Mendeleev quickly redrew his table, organizing the elements based off what he had noticed from the patterns. He left space on his table, knowing more elements would be discovered in the future. He had just created the first Periodic Table of Elements.
