A simplified explanation of the periodic table lesson 2021

Study the periodic table of elements for important and fun chemistry courses. The periodic table contains many different advantages and characteristics to explain the lesson on the periodic table. Explanation of the lesson on the periodic table. The periodic table is a table of the known chemical elements, which number 118, of which 92 exist in nature, while the remaining elements were prepared in the laboratory, and this table is made or arranged according to the number Atomic element. The electronic configuration and similar chemical properties of each group of elements. In general, the elements on the left are metals and the nonmetals on the right. Where elements with similar chemical behavior are placed in the same column. The periodic table is divided into rows and columns, called periods, and columns by groups. In the periodic table there are six groups that have distinct names other than the number assigned to them. For example, the elements in group number 18 in the periodic table are known as (noble gases) and the elements in group 17 are known as (halogens). There are also some sublevels associated with filling the orbitals. Atomicity. Russian chemist Dmitri Mendeleev was the first to draw up a periodic table of the elements and publish it in 1869. This table was subsequently developed several times based on Mendeleev's predictions, most of which turned out to be correct, and the periodic table was expanded. By discovering or inventing new elements. The development of the periodic table. As we mentioned, the first periodic table was published in 1869 and published by the scientist (Mendeleev). Mendeleev's table contained only 63 elements arranged according to their atomic weights, but he (Mendeleev) left some gaps in his table, waiting for the discovery of other chemical elements, and determined the chemical properties of the elements in those gaps. Amazingly, these predictions were correct and were discovered several years later From Mendeleev's program. There were also many attempts to list the known elements before the appearance of Mendeleev, the first of which was made by the Frenchman Lavoisier, then followed by Dalton, who classified the elements using their atomic mass. Many developments were made in the periodic table after Mendeleev until the scientist (Morley) arranged the elements in the table according to number The atomic number of each chemical element. It remained this way until the periodic table was developed into its modern form, and the elements on it were arranged by atomic number and electron-filled energy levels for each element. The elements were divided into 18 groups, ranging from left to right and from top to bottom, and the atomic number of each element gradually increased. At the bottom of the table there are two groups of elements divided into two rows, each row containing 14 elements. These elements are called (transition elements) and they are very similar in chemical properties, and are difficult to separate if mixed together. The first series is known as the lanthanides and the second series is called the actinides. The periodic table begins with hydrogen, with atomic number 1, and ends with eugene, which has atomic number 118. Uses of Table D