Differences And Similarities Between Dmitri Mendeleev And The Modern Periodic Table

The periodic table is a very identifiable symbol in everything science. There is one hanging in almost every chemistry class. But, the one we know is not what it always was. Before our modern periodic table there was the periodic table that Dmitri Mendeleev constructed. There are many differences and similarities between the Modern Periodic Table and Mendeleev’s Periodic Table. Just for example, the modern periodic table arranges elements in order of increasing atomic number. Mendeleev’s ordered them based upon increasing atomic weight. Another difference is that the modern periodic table has some elements that Mendeleev had not found. One of these family of elements are the non-reactive noble gases. There are also no gaps in the current Periodic Table. In Mendeleev’s version, he had gaps where elements had not been found yet. The last difference is that the lanthanides and actinides are listed in a separate block. Mendeleev did not do this because these elements had not been discovered. He just had them placed among the normal elements. Some similarities between the tables are as follows. Both Mendeleev and the current Periodic Table noticed that some elements had similar physical characteristics and they decided to arrange theme according to the characteristics. One other example is that Mendeleev and the current Periodic table both …show more content…
We use this method because when Mendeleev used atomic weight it made some of the elements skewed. For example, if you take the elements Te (Tellurium) and I (Iodine) they would not be in the correct order according to atomic weight, Te and I would need to be reversed. If they were reversed, then Iodine would not be in the same column as the other halogens. This is the reason we now arrange the elements of the periodic table according to increasing atomic