Dmitri Mendeleev: The Creation Of The Periodic Table

Chemists have always looked for a way to arrange the elements to reflect their properties and similarities. The modern periodic table lists the elements in order of increasing atomic number, but it wasn’t always like this. First the table was ordered by atomic masses. This was due to the lacking knowledge of sub-atomic particles. The creation of the modern periodic table took several differents ideas to finally arrive at what it is today. The most recognized person for discovering the periodic table is Dmitri Mendeleev. But several other chemists should be credited just as much. I’m going to take you down through the creation of the table as scientists and discoveries progress. A French geology teacher made a significant step towards a

He produced several periodic tables from 1864 to 1870. His first table contained 28 elements. These consisting mainly of the main group, but in 1868 he included the metals in a much more developed table. This table listed elements in order of atomic weight, with elements with the same valency arranged in vertical lines, strikingly similar to Mendeleev’s table. Sadly for Meyer, his wasn’t published until after Mendeleev’s was. This led to him getting no original credit for his ideas. Although Meyer was the first person to recognize the periodic trends in the properties in elements. He graphed this which was recognized

Mendeleev discovered the periodic table while attempting to organise the elements in February of 1869. He did so by writing the properties of the elements on pieces of card and arranging and rearranging them until he realised that, by putting them in order of increasing atomic weight, certain types of element regularly occurred. For example, a reactive non-metal was directly followed by a very reactive light metal and then a less reactive light metal. Initially, the table had similar elements in horizontal rows, but he soon changed them to fit in vertical columns, as we see today. Not only did Mendeleev arrange the elements in the correct way, but if an element appeared to be in the wrong place due to its atomic weight, he moved it to where it fitted with the pattern he had discovered. The real genius of Mendeleev’s achievement was to leave gaps for undiscovered elements. He even predicted the properties of five of these elements and their compounds. And over the next 15 years, three of these elements were discovered and Mendeleev’s predictions shown to be incredibly accurate. The discovery of the noble gases during the 1890s by William Ramsay initially seemed to contradict Mendeleev’s work, until he realised that actually they were further proof of his system, fitting in as the final