The elements of group 18 of the modern periodic table are considered noble gases. The electronic configuration of the first element (helium) of this group is 1s2. Remains all elements (neon, argon, krypton, xenon and radon) have their outer shell electronic configuration is ns2np6. Since the byte of these elements is complete, they are very stable elements. In 1869, Dmitri Mendeleev and Lothar Meyer independently established the law of periods. The first periodic table was developed by Mendeleev and soon followed by Meyer. Each grouped the elements according to their mass and suggested that these properties be reproduced regularly. The periodic law is considered one of the most important concepts in chemistry. While studying chemical elements, their properties and chemical reactions, every chemist uses periodic law, consciously or not.

The development of the modern periodic table was motivated by the law of periods. The atomic number is equal to the number of electrons or protons in a neutral atom. Having known the fundamental unity of the elements, scientists now had a clear idea of the quantum numbers and the electronic configuration of the elements in the periodic table. After knowing the periodic law, chemists noticed that there is an analogy between the 94 natural chemical elements. This analogy has made people more curious about the chemistry of these elements. Scientists have produced various artificial elements. A new periodic table was developed on the basis of the modern law of periods by modifying Mendeleev`s periodic table. The periodic law was formulated on the basis of observations made by scientists in the 19th century.

In particular, the contributions of Lothar Meyer and Dmitri Mendeleev highlighted trends in the properties of elements. They independently proposed a periodic law in 1869. The periodic table organized the elements to reflect the periodic law, although scientists at the time had no explanation as to why the properties followed a trend. Periodic table, in the complete periodic table of elements, in chemistry the organized arrangement of all chemical elements in order of ascending atomic number – that is, the total number of protons in the atomic nucleus. When chemical elements are arranged in this way, there is a recurring pattern called “periodic law” in their properties, in which elements in the same column (group) have similar properties. The first discovery, made by Dmitry I Mendeleyev in the middle of the 19th century. It was of inestimable importance for the development of chemistry. In a given period of time, the electronic configuration of the valence shell of any two elements is not the same. For this reason, elements have different chemical properties over time, with periodic left-to-right gradation for their physical properties. This is called a periodic property.

Groups consist of elements that have a similar electronic configuration of the outer layer in their atoms. Previously, groups were called IA,. VIIIA, VIII, IB. VIIB and 0. But now they are called 1, 2, 3. 18. In the modern periodic table, the periods are the seven horizontal series. The principal quantum number `n` determines the period of the element. The principal quantum number (n) is one of four quantum numbers (n, l, m and s).

This tells us something about the main electron shell. For example, if n=3, the main shell is specified as 3. The groups in the periodic table are displayed as vertical columns numbered from 1 to 18. The elements of a group have very similar chemical properties, resulting from the number of valence electrons present – that is, the number of electrons in the outermost shell of an atom. Periodic trends are common patterns in the periodic table that show us different aspects of an element such as electronegativity, atomic radius or ionizing strength. The periodic law tells us that when grouped by atomic number, certain properties of the elements appear periodically. The periodic table is a tabular arrangement of chemical elements ordered by atomic numbers, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson. The atomic number of an element is the number of protons in the nucleus of an atom of that element. Hydrogen has 1 proton and Oganesson has 118.

The modern periodic table is developed according to the law of periods and a Mendeleev periodic table. In the second half of the 18th century, Mendeleev made his periodic table. Scientists at the time knew nothing about the internal structure of the atom. If you still have doubts about the periodic law and want to know more about class 10 of the periodic table, read our introduction to the periodic table for more details. The periodic table has two lines at the bottom, which are usually separated from the body of the table. These lines contain elements from the lanthanide and actinide series, typically 57 to 71 (lanthanum to lutetium) and 89 to 103 (actinium to lawrencian) respectively. There is no scientific reason for this. It is made only to make the table more compact. The classification of elements in the periodic table can be done in four ways according to their electronic configurations: The basic idea of the periodic table is to have an organized arrangement of all known elements. Then, in 1869, following an extensive correlation of the atomic properties and weights of the elements, with particular attention to valence (that is, the number of single bonds that the element can form), Mendeleev proposed the periodic law, according to which “elements arranged according to the size of atomic weights show a periodic change in properties”. Lothar Meyer independently came to a similar conclusion, which was published after Mendeleev`s essay appeared. This is only a brief description of the periodic table and classification of elements.

To learn more, register for BYJU`S and download BYJU`S – the learning app. Lanthanides and actinides, which are at the lower end of the periodic table, fall into the category of internal transition elements. In these elements, the orbitals 4f and 5f are partially filled, which gives them special properties.