The periodic table is the arrangement of chemical elements according to their atomic number. Its structure is divided into sections, each of which has its own special meaning and function. 1. Cycle.
The horizontal rows in the periodic table are called periods. The number of electron shells of an element is the same in each cycle. The ordinal number of a period is the number of electron layers that the period has. There are 7 cycles in total.
Periods are a large group of elements in the periodic table that are arranged in a complete cycle according to the magnitude of the atomic number. The order in which the periods are arranged is determined by the number of electron shells of the element, the more electron shells there are, the higher the period. Currently, there are seven periods in the periodic table, which are labeled periods 1 to 7. 2. There are 18 vertical rows in the periodic table of the group elements. It is called a family (the first rows are combined into one family). The outermost number of electrons is the same for each element of this group.
Families are another important part of the periodic table that includes elements in the same column. Families can be further subdivided into primary and secondary families. The main group of elements refers to a class of elements with almost constant electron numbers in the outermost shell, and their chemical properties are relatively stable. The number of outermost electrons of the subgroup elements will change greatly, and their chemical properties are relatively active. In the periodic table, the labeling of a family is denoted by the letters A or B, where a represents the main group and B represents the minor group. 3. Transition metalsTransition metals refer to the secondary group elements in the middle of the main group from period 4 to period 7 in the periodic table, which have special electronic configurations and chemical properties. The atoms of transition metals have multiple variable valence states, so they have many different coordination modes and reactivity in chemical reactions. Transition metals have a wide range of applications in industrial production and scientific research, such as catalysts, drug synthesis, electroplating, etc. 4. Lanthanide and actinide Lanthanide and actinide are the third subgroup special series of periods 5 and 6 in the periodic table, these elements have higher atomic numbers and similar electronic configuration laws, so they also have certain similarities in chemical properties. The elemental elements of lanthanides and actinides and their compounds have a wide range of applications in scientific research and industrial production, such as nuclear energy, superconducting materials, etc. The structure of the periodic table is arranged according to the atomic number size of the elements, and it includes several parts such as period, group, transition metal, lanthanide, and actinide. Each of these parts has its own special electronic configuration and chemical properties, so it has a wide range of applications in scientific research and industrial production. By gaining an in-depth understanding of the structure of the periodic table, we can better grasp the properties and uses of the elements, providing important support for scientific research and technological innovation.