The Lanthanides and the Actinides are arranged into different blocks. The modern periodic table consists of 18 columns called groups and 7 rows called periods. Therefore, it gives meaning to the electronic configuration of each element. The basis of the modern periodic table is the atomic number of elements the physical and chemical properties of the elements are treated as periodic functions of their atomic numbers. They are the atoms of the same element with differing weights. However, Mendeleev’s periodic table didn’t support the existence of the isotopes.
He then released a second version of his periodic table where the elements were grouped in columns numbered l-Vlll, depending on element’s oxidation state. Mendeleev’s first periodic table had the elements with similar properties grouped in rows. The elements Tellurium and Iodine is a good example for this. Gallium and Geranium were two such elements.Īlso in some cases, Mendeleev didn’t strictly follow the rule of ordering the atoms according to their atomic weights he placed the elements giving priority to their chemical properties, so they can be grouped accurately. Therefore, Mendeleev’s periodic table had empty spaces/gaps, so that these elements, once found can be then included. There were other scientists who have worked on tabulating information of the elements even before Mendeleev, however, he was the first scientist to come up with a periodic trend to predict the properties of elements which were not discovered at that time. The basis of Mendeleev’s periodic table was categorizing the elements according to their physical and chemical characteristics with regard to their atomic weights. The main difference between Mendeleev and Modern Periodic Table is that Mendeleev’s periodic table orders the elements based on their atomic mass whereas Modern periodic table orders the elements based on their atomic number. The rows in the periodic table are called periods, and they represent sets of elements that get repeated due the possession of similar properties. The columns in the periodic table are called groups, and they group together elements with similar properties. Hence, the term ‘periods’ came into use, resembling this character of repetition. Mendeleev was able to identify that chemical properties of the elements began repeating each time after a certain number of elements. This feature is the main building block for the modern periodic table as well. The Russian Chemist/Professor Dmitri Mendeleev was the first to come up with a structure for the periodic table with columns and rows.
#Mendeleev periodic table series
The modern periodic table was created after a series of different versions of the periodic table. The periodic table is the arrangement of chemical elements according to their chemical and physical properties. Main Difference – Mendeleev vs Modern Periodic Table
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