The periodic table or Mendeleev’s table is the table that contains all the chemical elements discovered by scientists, and the chemical elements are arranged based on the value of the increase in atomic numbers.
In addition, all the elements that have the same properties were arranged within the same column or row, so it is one of the most important tools used in the field of science in general, and in the field of chemistry in particular.
A chemical element is any substance that cannot be decomposed into simpler substances through normal chemical processes.
Chemical elements constitute all the basic substances of the universe, and at the moment there are 118 known chemical elements, of which 94 are natural with 24 synthetic elements prepared in a laboratory.
Elements can also be combined with each other to form a wide variety of more complex substances called compounds, and the elements are arranged according to their atomic number in a table called the modern periodic table.
The periodic table of the elements is defined as an organized matrix of all chemical elements based on the increase in their atomic numbers, i.e. the total number of protons in the atomic nucleus, electronic distribution, and recurring chemical properties.
These elements are arranged in this table according to the increase in atomic number from left to right and top to bottom.
The group of elements in the same row in the periodic table is known as the period, while the group of elements belonging to the same column is called the group.
It should be noted that the beginning of the discovery of the dates of the periodic table back to the middle of the nineteenth century by the scientist “Dmitriy Mendeleev”.
The importance of the periodic table
The periodic table is one of the most important tools that have been discovered in the history of chemistry, and this table is of great importance to those who use it, and we will review together some of the things that indicate the importance of this table:
- Both the old periodic table, and the modern periodic table are equally important; It is the organization of elements based on their similar properties, by determining the properties of each element by looking only at its position in the periodic table.
- The periodic table allows you to know the chemical elements accurately, as each element has its chemical symbol, carbon has its symbol C, oxygen has its symbol O, sulfur has its symbol S, and hydrogen has its symbol H.
- Before all the elements were identified and discovered, the periodic table was used to determine the physical, as well as chemical properties of each of the elements present.
- The periodic table is important now because it can be used for elements that have not yet been discovered or identified, despite the fact that most of these elements are radioactive, and function once they are broken down into existence in the form of the previously known elements.
- The importance of the periodic table in the educational process is that it can help both the learner and the teacher, by determining the amount of chemical reactions that each element can participate in by itself, and this is considered an alternative to the fatigue resulting from memorizing, as facts and figures for each element separately.
- The periodic table is important by predicting every property of each of the elements on the table, even those that scientists haven’t discovered yet.
- The periodic table provides many important information about the elements, as well as how these elements relate to each other or the way they interact with others, and the periodic table can be considered as an easy-to-use reference.
- Each of the columns and rows in the periodic table is distinguished in that they refer to elements that have similar properties or that they share some things.
- The periodic table provides some of the most valuable information that helps provide balanced chemical equations. The periodic table helps balance these equations in a very easy way.
Characteristics of the periodic table
The elements of the periodic table have many properties, among which are the following:
- The periodic table contains 118 elements, and the search for innovation and new elements continues.
- Most of the elements in the periodic table are metals, which are alkaline metals, alkaline earth metals, base metals and transition metals.
- The periodic table has seven horizontal cycles, and 18 groups (vertical columns).
- The rows of the table (cycles), the element number of the cycle, are called the highest energy level, for unpaired electrons.
- The periodic table is based on the classification of elements based on the increase in their atomic numbers, as the size of the atom decreases when moving from left to right in one cycle, and also increases when moving from top to bottom in one group.
- Elements of one group are similar in properties, and have the same arrangement of electrons for the last orbital.
- Group I, II, and III elements tend to lose electrons and become more electronegative, and Group IV, V, and VI elements tend to gain electrons and become more electronegative.
- Each cycle in the table ends with an inert (noble) element, which has the electrons of its last orbit full.
- The valence electrons, or the electrons of the last orbital of an element, determine which cycle number it belongs to.
- At the bottom of the periodic table there are two long chains of elements, the first chain is called the lanthanides and the second is the actinides, and each chain contains 14 elements, and these chains belong to the transitional group of elements, and they were placed at the bottom of the table to save space.
- The elements in the table are classified into metals and non-metals, with semi-metals divided between them.
The electronegativity decreases as we move from right to left of the elements in the table.
Names of the elements of the periodic table
The periodic table consists of a group of chemical elements, as the current table includes 118 chemical elements, and the following is a list of the names of the elements of the periodic table:
The atrium (Y).
Nihonium «anon triium» (NH).
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