Periodic table name sign pronunciation. Designation, pronunciation, names and symbols of chemical elements. Chemicals and their pronunciation

How to use the periodic table? For an uninitiated person, reading the periodic table is the same as for a gnome looking at the ancient runes of the elves. And the periodic table can tell you a lot about the world.

In addition to serving you well in the exam, it is also simply irreplaceable when solving a huge number of chemical and physical problems. But how to read it? Fortunately, today everyone can learn this art. In this article we will tell you how to understand the periodic table.

Periodic table chemical elements(periodic table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus.

History of the creation of the Table

Dmitry Ivanovich Mendeleev was not a simple chemist, if anyone thinks so. He was a chemist, physicist, geologist, metrologist, ecologist, economist, oil worker, aeronaut, instrument maker and teacher. During his life, the scientist managed to conduct a lot of fundamental research in various fields of knowledge. For example, it is widely believed that it was Mendeleev who calculated the ideal strength of vodka - 40 degrees.

We don’t know how Mendeleev felt about vodka, but we know for sure that his dissertation on the topic “Discourse on the combination of alcohol with water” had nothing to do with vodka and considered alcohol concentrations from 70 degrees. With all the merits of the scientist, the discovery periodic law chemical elements - one of the fundamental laws of nature, brought him the widest fame.

There is a legend according to which a scientist dreamed of the periodic table, after which all he had to do was refine the idea that had appeared. But, if everything were so simple.. This version of the creation of the periodic table, apparently, is nothing more than a legend. When asked how the table was opened, Dmitry Ivanovich himself answered: “ I’ve been thinking about it for maybe twenty years, but you think: I was sitting there and suddenly... it’s done.”

In the mid-nineteenth century, attempts to arrange the known chemical elements (63 elements were known) were undertaken in parallel by several scientists. For example, in 1862, Alexandre Emile Chancourtois placed elements along a helix and noted the cyclic repetition of chemical properties.

Chemist and musician John Alexander Newlands proposed his version of the periodic table in 1866. An interesting fact is that the scientist tried to discover some kind of mystical musical harmony in the arrangement of the elements. Among other attempts, there was also Mendeleev’s attempt, which was crowned with success.

In 1869, the first table diagram was published, and March 1, 1869 is considered the day the periodic law was opened. The essence of Mendeleev's discovery was that the properties of elements with increasing atomic mass do not change monotonically, but periodically.

The first version of the table contained only 63 elements, but Mendeleev made a number of very unconventional decisions. So, he guessed to leave space in the table for still undiscovered elements, and also changed the atomic masses of some elements. The fundamental correctness of the law derived by Mendeleev was confirmed very soon, after the discovery of gallium, scandium and germanium, the existence of which was predicted by the scientist.

Modern view of the periodic table

Below is the table itself

Today, instead of atomic weight (atomic mass), the concept of atomic number (the number of protons in the nucleus) is used to order elements. The table contains 120 elements, which are arranged from left to right in order of increasing atomic number (number of protons)

The table columns represent so-called groups, and the rows represent periods. The table has 18 groups and 8 periods.

1. The metallic properties of elements decrease when moving along a period from left to right, and in reverse direction– increase.
2. The sizes of atoms decrease when moving from left to right along periods.
3. When moving from top to bottom in a group, recovery factors increase metallic properties.
4. Oxidizing and non-metallic properties increase as you move along a period from left to right.

What do we learn about an element from the table? For example, let's take the third element in the table - lithium, and consider it in detail.

First of all, we see the element symbol itself and its name below it. In the upper left corner is the atomic number of the element, in which order the element is arranged in the table. The atomic number, as already mentioned, is equal to the number of protons in the nucleus. The number of positive protons is usually equal to the number of negative electrons in an atom (with the exception of isotopes).

The atomic mass is indicated under the atomic number (in this version of the table). If you round atomic mass to the nearest integer, we get the so-called mass number. The difference between the mass number and the atomic number gives the number of neutrons in the nucleus. Thus, the number of neutrons in a helium nucleus is two, and in lithium it is four.

Our course “Periodical Table for Dummies” has ended. In conclusion, we invite you to watch a thematic video, and we hope that the question of how to use periodic table Mendeleev, has become more clear to you. We remind you that it is always more effective to study a new subject not alone, but with the help of an experienced mentor. That is why you should never forget about the student service, which will gladly share its knowledge and experience with you.

2.1. Chemical language and its parts

Humanity uses many different languages. Except natural languages(Japanese, English, Russian - more than 2.5 thousand in total), there are also artificial languages , for example, Esperanto. Among artificial languages ​​there are languages various sciences. So, in chemistry they use their own, chemical language.
Chemical language– a system of symbols and concepts designed for a brief, succinct and visual recording and transmission of chemical information.
A message written in most natural languages ​​is divided into sentences, sentences into words, and words into letters. If we call sentences, words and letters parts of language, then we can identify similar parts in chemical language (Table 2).

Table 2.Parts of chemical language

It is impossible to master any language immediately; this also applies to a chemical language. Therefore, for now you will only get acquainted with the basics of this language: learn some “letters”, learn to understand the meaning of “words” and “sentences”. At the end of this chapter you will be introduced to names chemical substances are an integral part of the chemical language. As you study chemistry, your knowledge of chemical language will expand and deepen.

CHEMICAL LANGUAGE.
1.What artificial languages ​​do you know (other than those mentioned in the text of the textbook)?
2.Than natural languages different from artificial ones?
3. Do you think it is possible to describe chemical phenomena without using chemical language? If not, why not? If so, what would be the advantages and disadvantages of such a description?

The symbol for a chemical element represents the element itself or one atom of that element.
Each such symbol is an abbreviated Latin name of a chemical element, consisting of one or two letters of the Latin alphabet (for the Latin alphabet, see Appendix 1). The symbol is written with a capital letter. Symbols, as well as Russian and Latin names of some elements, are given in Table 3. Information about the origin of the Latin names is also given there. General rule There is no pronunciation of the symbols, therefore Table 3 also shows the “reading” of the symbol, that is, how this symbol is read in the chemical formula.

It is impossible to replace the name of an element with a symbol in oral speech, but in handwritten or printed texts this is allowed, but not recommended. Currently, 110 chemical elements are known, 109 of them have names and symbols approved by the International Union of Pure and Applied Chemistry (IUPAC).
Table 3 provides information on only 33 elements. These are the elements that you will encounter first when studying chemistry. Russian names (in alphabetical order) and symbols of all elements are given in Appendix 2.

Table 3.Names and symbols of some chemical elements

Used to designate chemical substances chemical formulas.

For molecular substances, a chemical formula can denote one molecule of this substance.
Information about a substance may vary, so there are different types chemical formulas .
Depending on the completeness of the information, chemical formulas are divided into four main types: protozoa, molecular, structural And spatial.

Subscripts in the simplest formula do not have a common divisor.
The index "1" is not used in formulas.
Examples of the simplest formulas: water - H 2 O, oxygen - O, sulfur - S, phosphorus oxide - P 2 O 5, butane - C 2 H 5, phosphoric acid– H 3 PO 4, sodium chloride (table salt) – NaCl.
The simplest formula of water (H 2 O) shows that the composition of water includes the element hydrogen(H) and element oxygen(O), and in any portion (a portion is a part of something that can be divided without losing its properties.) of water, the number of hydrogen atoms is doubled more number oxygen atoms.
Number of particles, including number of atoms, denoted by a Latin letter N. Denoting the number of hydrogen atoms – N H, and the number of oxygen atoms is N O, we can write that

Or N H: N O=2:1.

The simplest formula of phosphoric acid (H 3 PO 4) shows that phosphoric acid contains atoms hydrogen, atoms phosphorus and atoms oxygen, and the ratio of the numbers of atoms of these elements in any portion of phosphoric acid is 3:1:4, that is

NH: N P: N O=3:1:4.

The simplest formula can be compiled for any individual chemical substance, and for molecular substance, in addition, can be compiled molecular formula.

Examples molecular formulas: water – H 2 O, oxygen – O 2, sulfur – S 8, phosphorus oxide – P 4 O 10, butane – C 4 H 10, phosphoric acid – H 3 PO 4.

Non-molecular substances do not have molecular formulas.

The sequence of writing element symbols in simple and molecular formulas is determined by the rules of chemical language, which you will become familiar with as you study chemistry. The information conveyed by these formulas is not affected by the sequence of symbols.

Of the signs reflecting the structure of substances, we will only use for now valence stroke("dash"). This sign shows the presence between the atoms of the so-called covalent bond(what type of connection this is and what its features are, you will soon find out).

In a water molecule, an oxygen atom is connected by simple (single) bonds to two hydrogen atoms, but the hydrogen atoms are not connected to each other. This is precisely what the structural formula of water clearly shows.

Another example: the sulfur molecule S8. In this molecule, 8 sulfur atoms form an eight-membered ring, in which each sulfur atom is connected to two other atoms by simple bonds. Compare the structural formula of sulfur with volumetric model its molecules shown in Fig. 3. Please note that the structural formula of sulfur does not convey the shape of its molecule, but only shows the sequence of connection of atoms by covalent bonds.

The structural formula of phosphoric acid shows that in the molecule of this substance one of the four oxygen atoms is connected only to the phosphorus atom by a double bond, and the phosphorus atom, in turn, is connected to three more oxygen atoms by single bonds. Each of these three oxygen atoms is also connected by a simple bond to one of the three hydrogen atoms present in the molecule.

Compare the following three-dimensional model of a methane molecule with its spatial, structural and molecular formula:

In the spatial formula of methane, wedge-shaped valence strokes, as if in perspective, show which of the hydrogen atoms is “closer to us” and which is “further from us”.

Sometimes the spatial formula indicates bond lengths and angles between bonds in a molecule, as is shown in the example of a water molecule.

Non-molecular substances do not contain molecules. For convenience chemical calculations in a non-molecular substance, the so-called formula unit.

Examples of the composition of formula units of some substances: 1) silicon dioxide (quartz sand, quartz) SiO 2 – a formula unit consists of one silicon atom and two oxygen atoms; 2) sodium chloride (table salt) NaCl – the formula unit consists of one sodium atom and one chlorine atom; 3) iron Fe - a formula unit consists of one iron atom. Like a molecule, a formula unit is the smallest portion of a substance that retains its chemical properties.

Table 4

Information conveyed by different types of formulas

Let us now consider, using examples, what information different types of formulas give us.

1. Substance: acetic acid. The simplest formula is CH 2 O, molecular formula is C 2 H 4 O 2, structural formula

The simplest formula tells us that
1) included acetic acid includes carbon, hydrogen and oxygen;
2) in this substance the number of carbon atoms relates to the number of hydrogen atoms and the number of oxygen atoms, as 1: 2: 1, that is N H: N C: N O = 1:2:1.
Molecular formula adds that
3) in a molecule of acetic acid there are 2 carbon atoms, 4 hydrogen atoms and 2 oxygen atoms.
Structural formula adds that
4, 5) in a molecule two carbon atoms are connected to each other by a simple bond; one of them, in addition, is connected to three hydrogen atoms, each with a single bond, and the other to two oxygen atoms, one with a double bond and the other with a single bond; the last oxygen atom is still connected by a simple bond to the fourth hydrogen atom.

2. Substance: sodium chloride. The simplest formula is NaCl.
1) Sodium chloride contains sodium and chlorine.
2) In this substance, the number of sodium atoms is equal to the number of chlorine atoms.

3. Substance: iron. The simplest formula is Fe.
1) This substance contains only iron, that is, it is a simple substance.

4. Substance: trimetaphosphoric acid . The simplest formula is HPO 3, molecular formula is H 3 P 3 O 9, structural formula

1) Trimetaphosphoric acid contains hydrogen, phosphorus and oxygen.
2) N H: N P: N O = 1:1:3.
3) The molecule consists of three hydrogen atoms, three phosphorus atoms and nine oxygen atoms.
4, 5) Three phosphorus atoms and three oxygen atoms, alternating, form a six-membered cycle. All connections in the cycle are simple. Each phosphorus atom is, in addition, connected to two more oxygen atoms, one with a double bond and the other with a single bond. Each of the three oxygen atoms connected by simple bonds to phosphorus atoms is also connected by a simple bond to a hydrogen atom.

Table 5.Examples of different types of formulas for some substances-

All names of chemical elements come from Latin language. This is necessary primarily so that scientists different countries could understand each other.

Chemical symbols of elements

Elements are usually designated chemical signs(symbols). According to the proposal of the Swedish chemist Berzelius (1813), chemical elements are designated by the initial or initial and one of the subsequent letters of the Latin name of a given element; The first letter is always uppercase, the second lowercase. For example, hydrogen (Hydrogenium) is designated by the letter H, oxygen (Oxygenium) by the letter O, sulfur (Sulfur) by the letter S; mercury (Hydrargyrum) - letters Hg, aluminum (Aluminium) - Al, iron (Ferrum) - Fe, etc.

Rice. 1. Table of chemical elements with names in Latin and Russian.

Russian names of chemical elements are often Latin names with modified endings. But there are also many elements whose pronunciation differs from the Latin source. These are either native Russian words (for example, iron), or words that are translations (for example, oxygen).

Chemical nomenclature

Chemical nomenclature is the correct name for chemical substances. The Latin word nomenclatura translates as “list of names”

At the early stage of the development of chemistry, substances were given arbitrary, random names (trivial names). Highly volatile liquids were called alcohols, which included “hydrochloric alcohol” - aqueous solution hydrochloric acid, “silitry alcohol” – nitric acid, “ammonia” is an aqueous solution of ammonia. Oily liquids and solids called oils, for example, concentrated sulfuric acid was called “oil of vitriol”, arsenic chloride was called “arsenic oil”.

Sometimes substances were named after their discoverer, for example, “Glauber’s salt” Na 2 SO 4 * 10H 2 O, discovered by the German chemist I. R. Glauber in the 17th century.

Rice. 2. Portrait of I. R. Glauber.

Ancient names could indicate the taste of substances, color, smell, appearance, medical action. One substance sometimes had several names.

By the end of the 18th century, chemists knew no more than 150-200 compounds.

The first system of scientific names in chemistry was developed in 1787 by a commission of chemists headed by A. Lavoisier. Lavoisier's chemical nomenclature served as the basis for the creation of national chemical nomenclatures. In order for chemists from different countries to understand each other, the nomenclature must be uniform. Currently, the construction of chemical formulas and names inorganic substances is subject to a system of nomenclatural rules created by a commission of the International Union of Pure and Applied Chemistry (IUPAC). Each substance is represented by a formula, in accordance with which the systematic name of the compound is constructed.

Rice. 3. A. Lavoisier.

What have we learned?

All chemical elements have Latin roots. Latin names of chemical elements are generally accepted. They are transferred into Russian using tracing or translation. however, some words are originally Russian meaning, such as copper or iron. Chemical nomenclature All chemical substances consisting of atoms and molecules obey. The system of scientific names was first developed by A. Lavoisier.

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Instructions

The periodic table is a multi-story “house” in which it is located large number apartments Each “tenant” or in his own apartment under a certain number, which is permanent. In addition, the element has a “surname” or name, such as oxygen, boron or nitrogen. In addition to this data, each “apartment” contains information such as relative atomic mass, which may have exact or rounded values.

As in any house, there are “entrances”, namely groups. Moreover, in groups the elements are located on the left and right, forming. Depending on which side there are more of them, that side is called the main one. The other subgroup, accordingly, will be secondary. The table also has “floors” or periods. Moreover, periods can be both large (consist of two rows) and small (have only one row).

The table shows the structure of an atom of an element, each of which has a positively charged nucleus consisting of protons and neutrons, as well as negatively charged electrons rotating around it. The number of protons and electrons is numerically the same and is determined in the table by the serial number of the element. For example, the chemical element sulfur is #16, therefore it will have 16 protons and 16 electrons.

To determine the number of neutrons (neutral particles also found in the nucleus), subtract the relative atomic mass of the element from its serial number. For example, iron has a relative atomic mass of 56 and an atomic number of 26. Therefore, 56 – 26 = 30 protons for iron.

Electrons are located at different distances from the nucleus, forming electron levels. To determine the number of electronic (or energy) levels, you need to look at the number of the period in which the element is located. For example, aluminum is in the 3rd period, therefore it will have 3 levels.

By the group number (but only for the main subgroup) you can determine the highest valency. For example, elements of the first group of the main subgroup (lithium, sodium, potassium, etc.) have a valence of 1. Accordingly, elements of the second group (beryllium, magnesium, calcium, etc.) will have a valency of 2.

You can also analyze the properties of elements using the table. From left to right, metallic properties weaken, and non-metallic properties increase. This is clearly seen in the example of period 2: it begins alkali metal sodium, then alkaline earth metal magnesium, followed by the amphoteric element aluminum, then non-metals silicon, phosphorus, sulfur, and the period ends with gaseous substances - chlorine and argon. In the next period, a similar dependence is observed.

From top to bottom, a pattern is also observed - metallic properties increase, and non-metallic properties weaken. That is, for example, cesium is much more active compared to sodium.