mendeleev-presents-first-periodic-table

On March 6, 1869, Dmitri Mendeleev presents the first periodic table of the elements to the Russian Chemical Society. From the article:

"Mendeleev Presents First Periodic Table | History Channel on Foxtel
6 March 1869

Mendeleev Presents First Periodic Table
On this day in 1869, Russian chemist Dmitri Mendeleev presented the first periodic table to the Russian Chemical Society. Representing the culmination of a century of growth in the knowledge of chemical properties, the periodic table itself is a visual representation of the periodic law, which states that when elements are ordered according to atomic weight or number, certain properties of elements repeat periodically.

Born in Siberia to a teacher of fine arts, politics, and philosophy, Mendeleev endured a difficult childhood and youth. His father became blind and lost his teaching position, his mother was forced to work and reopened her family’s glass factory, then his father died and his mother’s glass factory burned to the ground, after which Mendeleev moved to St Petersburg, contracted tuberculosis, then moved to the Crimean Peninsula. After his recovery, Mendeleev became a science master and returned to St Petersburg where he wrote his first book, married, and became a professor.

In 1868, the Russian chemist wrote the definitive textbook of his time, Principles of Chemistry. As he attempted to classify elements according to their chemical properties, Mendeleev noticed a curious pattern emerging. This pattern led him to create the periodic table. Though other scientists like John Newlands and Lothar Meyer had made advances in discovering and describing elements and suggesting they display periodicity, Mendeleev was unaware of their work and created his periodic table independently.

On 6 March 1869, Mendeleev presented his table to the Russian Chemical Society in a formal paper entitled, “The Dependence between the Properties of the Atomic Weights of the Elements.” Among his most important findings was that, if elements are arranged according to their atomic weight, a pattern resulted whereby similar properties for elements recurred periodically. Thus, the table could be used to predict properties of elements that had yet to be discovered, predictions that were later substantiated.

Eventually, Mendeleev’s table and findings led to the formulation of the periodic law, which states that chemical properties of elements are dependent on their atomic numbers. Elements in Mendeleev’s periodic table are arranged in periods, or rows, and groups, or columns. The periods are arranged according to atomic number and the groups include elements with the same electron configurations in their outer shells, which results in group elements sharing the similar chemical properties.

For his work, Mendeleev was recommended to receive the Nobel Prize in Chemistry in 1906 but was passed over due to politics. He died a year later, in 1907, at the age of 72. The radioactive element number 101, mendelevium, is named after him."