History of Mendeleev’s Table

1. Describe the evidence and chain of scientific arguments that led to Mendeleev’s Periodic Table and its acceptance by the scientific community, up through Moseley’s Law.

The Periodic Table

At the Karlsruhe conferencce, scientists met to set standards for organizing elements/atomic weights. Since chemists used different standards for atomic weights, it was difficult to share information. Cannizzaro, extending Avogadro’s findings in 1811, proposed that atomic weight should be based on the weight of particles in a mole of atoms.

Mendeleev was not the first to create a periodic table, but his was the first to be widely accepted. The table was created by arranging elements by increasing atomic mass and grouping them by similar properties. Mendeleev left gaps in his table for undiscovered elements and predicted their properties. He discovered that by ordering elements in increasing atomic weight order, similar chemical properties started to emerge at certain intervals. Throught his table, Mendeleev predicted the properties of 3 undescovered elements, boron, aluminum, and silicon. He also used the table to help develop and discover the noble gases, after Ramsay discovered Argon in 1894.