Understanding the periodic table is necessary for all the students. The basic knowledge of the periodic table is given in the ninth standard. After that, if a student takes a science subject, they should know the periodic table in depth. It is one of the most important topics of inorganic chemistry. It is the arrangement of all the chemical elements in ascending order of atomic number, that is the total volume of protons in the middle of an atom. When the chemical elements are so arranged, there is a repeating pattern known as the periodic law in their properties, where elements of the same column (group) have similar properties. It was not until the second decade of the twentieth century that it was recognized that the order of the elements in the periodic system was their atomic number, their integer equal to the positive charge of the nuclei. Atomic units are expressed in units of electrons. In the years that followed, great progress was made in explaining the periodic laws of the electronic structure of atoms and molecules. This increased the value of the law, which was used as much as it is today in the early 20th century when it expressed the only known relationship between the elements. The three main types of elements are metals, metals or semi-metals, and non-metals. Metallic characters are highest in the lower-left corner of the periodic table, while non-metallic elements are found most often in the upper right corner.