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Mandleev |
| Answer» \tMendeleev’s Periodic Table:\tMendeleev believed that the atomic mass of an element was the most fundamental property in classifying elements.\tMendeleev arranged elements in the increasing order of their atomic masses and observed that the elements showed repetition after certain intervals in their physical and chemical properties.\tHe arranged the known elements in the increasing order of their atomic masses in horizontal rows, till he encountered an element which had properties similar to the first element.\tMendeleev placed the element below the first element and started the second row of elements.\tProceeding in this way, he created the first periodic table containing 63 elements, arranged according to their properties.Mendeleev’s Periodic Law: The physical and chemical properties of elements are a periodic function of their atomic masses.\xa0Features of Mendeleev’s Periodic Table:\tThere are seven horizontal rows in the periodic table, numbered from 1 to 7. These seven rows are called periods.\tThere are eight vertical columns numbered from I to VIII. These eight columns are called groups. Groups I to VII are further divided into sub groups A and B.\tThe properties of elements in a particular period show regular gradation from left to right. | |