To be honest, the first time looking at the table, it is impossible to read it. Why are there gaps somewhere, and somewhere whole dozens of elements are included in one cell? By what principle were the volatile substances located at the end of the group, while those with more pronounced metallic properties are located closer to the beginning? Most of these questions are answered by chemistry lessons, where the teacher spends a lot of time teaching children to read the periodic table. But, if it has not been stored in memory, or something has remained unclear, it does not matter, everything is not so difficult.
Probably, many people have noticed that all the elements are arranged in order, and each has its own number. It characterizes the number of protons in the nucleus, as well as the number of electrons moving around it. The larger it is, the more levels, so–called "orbitals", on which they are able to move.
The next thing that draws attention is sometimes even a huge number at the bottom. This is the relative atomic mass of an element, which characterizes how much one mole of it will weigh. As a rule, it is measured in grams per mole, so it is not difficult to guess how light it is. As a rule, by the way, this is an average value, so it is written with numbers after the decimal point. The only exceptions are the elements standing in the seventh period, that is, radioactive.
Sometimes several numbers are also signed on the side, which in total give an ordinal number. This is not accidental. This is the arrangement of electrons along the same orbitals that were previously discussed. This is quite convenient for future use, but, unfortunately, is not always present.
The most important thing that remains at the end is the groups and periods in this table. Columns and lines, in simple words. This is one of the most important points characterizing the elements in the periodic table. To make it easier to remember, it is worth understanding that elements with similar chemical properties are usually located in the group, while they change in the period.
The period, as a rule, coincides with the valence shell of the element. As a rule, the more to the right the substance is located, the more pronounced its metallic (reducing) properties, while in the left part more emphasis is placed on oxidative.