Where do they come from names and symbols of chemical elements? Already in ancient Egypt, symbolic images were used to designate certain substances, which expressed whole words or concepts (Fig. 5.7).

In the Middle Ages, the number of alchemical symbols reached several thousand. And for the same substance there were dozens of different signs.

Chemical element symbol- its conventional designation.

In the second half of the XVIII century. scientists made futile attempts to streamline the chemical signs. It was not possible to designate each substance with a separate symbol due to the discovery of many new substances. Therefore, over time, the ancient alchemical symbols were replaced by chemical signs proposed by the English chemist J. Dalton. In the symbolism of Dalton, the atom of each element is depicted by a circle. On the image field, either dashes and dots, or the initial letters of the English names of the elements are indicated. The letter system of chemical signs is a convenient way of recording, storing and transmitting chemical information.

Dalton signs, although they had a certain distribution, were inconvenient for printing. Therefore, in 1814, the Swedish scientist J.Ya. Berzelius proposed only an alphabetic system of signs. The signs of the elements were composed either from the first letter of their Latin names, or from the first and one of the subsequent letters. So Berzelius achieved the maximum possible convergence of the symbol of a chemical element with its name.

Latin name of a chemical element	Symbol
	alchemical	according to J. Dalton	according to J. Ya. Berzelius
H ydrar g yrum
P lum b um

Table. Names and symbols of some chemical elements

Symbol	Pronunciation	latintitle	Modern name
			Russian	Ukrainian
		H hydrogenium		Hydrogen
		C arboneum
		N itrogenium		Nitrogen
		O xygenium	oxygen
		M a g nesium
	Aluminum	Al uminium	aluminum	Aluminum
		Si licium
		P hoshorus
		Z i n kum
	Argentum	A r g entum		Argentum material from the site
		S ta n num
		P lum b um
	Hydrargyrum	H ydrar g yrum		Mercury

Analyze the data given in the table. Compare modern Russian and Ukrainian names of chemical elements. Determine which of them are directly derived from Latin names.

Remember that the Russian names of chemical elements are common nouns, they are written with a lowercase letter. Modern Ukrainian names of chemical elements are their own, so they are written with a capital letter. In both cases, it is impossible in oral speech to replace the name of a chemical element with the pronunciation of its symbol. You should also not replace the name of an element with its symbol in manuscripts or printed texts.

On this page, material on the topics:

• Chemical elements and their pronunciation

• Chemical elements signs name pronunciation

• Symbolism of chemical elements abstract

• Sulfur notation in chemistry

• periodic table title sign pronunciation

Questions about this item:

Municipal state educational institution

"Popovo-Lezhachany secondary school"

District Seminar for Chemistry Teachers

Glushkovsky district, Kursk region

Open lesson in chemistry in grade 8 on the topic: "Signs of chemical elements"

Prepared by:

Kondratenko Olga Vasilievna,

chemistry and biology teacher

MKOU "Popovo-Lezhachanskaya" secondary school

Glushkovsky district, Kursk region

s.Popovo-Lyozhachi

Chemistry, grade 8

Date: 29.09.2015

Lesson #12

Subject:Signs of chemical elements

Target: to consolidate the knowledge and skills of students on the topics "Methods of knowledge in chemistry", "Pure substances and mixtures", "Chemical elements", "Relative atomic mass of chemical elements".

Lesson objectives:

educationals:

1. test the knowledge and skills of students on topics"Methods of knowledge in chemistry", "Pure substances and mixtures", "Chemical elements", "Relative atomic mass of chemical elements"using interactive learning tools;
2. generalize students' knowledge on the topics studied;
3. identify gaps in the assimilation of educational material.

Developing:

1. to develop chemical language, logical thinking, attention, memory, interest in modern chemical science, curiosity of students, the ability to draw conclusions and generalizations;
2. to form the skill of working with various sources of information in order to search and select the necessary material.

Educational:

1. to form a positive motivation for educational activities, a scientific outlook;
2. develop a culture of mental work; skills of business cooperation in the process of solving problems, working in groups;
3. to cultivate the ability to work in a team, courtesy, discipline, accuracy, diligence;
4. develop the ability to formulate and argue their own opinion, independence.

Planned results:

personal: readiness and ability of students to self-development, self-determination; responsible attitude to teaching; the ability to set goals and build life plans; formation of a communicative culture, the values ​​of a healthy and safe lifestyle;

metasubject: be able to set a goal and plan ways to achieve it, choosing more rational ways to solve this problem; learn to adjust their actions in connection with a change in the situation; be able to create, apply and transform signs and symbols, models and schemes for solving educational and cognitive problems; be able to consciously use speech means in accordance with the task of communication to express their thoughts and needs; be able to organize joint work with peers in a group; be able to find information in various sources; possess the skills of self-control, self-assessment;

subject:

know: basic chemical concepts "chemical element", "simple substance", "complex substance", signs of basic chemical elements; composition of simple and complex substances; the role of chemistry in human life and in solving environmental problems;

be able to: by the formula to distinguish a simple substance from a complex one; to distinguish a chemical element from a simple substance; analyze and objectively assess skills for the safe handling of substances; establish links between actually observed chemical phenomena and processes occurring in the microcosm; use various methods of studying substances.

Lesson type: knowledge control.

Forms of work: group, work in pairs, game.

Teaching methods: problem presentation, partially exploratory.

learning techniques: posing problem questions.

Means of education: computer, projector, Power Point presentation

Equipment for teacher and students: computer, projector, table "Periodic Table of Chemical Elements", laboratory stand, ring, porcelain cup, spirit lamp, filter paper, scissors, chemical beakers, glass rod, contaminated salt mixture, water.

Literature:

For the teacher:

1. Gorkovenko M. Yu. Lesson developments in chemistry grade 8 for the textbooks of O. S. Gabrielyan, L. S. Guzey, G. E. Rudzitis. - M: "VAKO", 2004;
2. Radetsky A. M., Gorshkova V. P. Didactic material: chemistry grades 8-9 - M: Education, 1997.

For a student:

Chemistry: inorganic chemistry: a textbook for grade 8 educational institutions / G. E. Rudzitis, F. G. Feldman. - M: "Enlightenment", 2014

During the classes:

I.Organizational moment (1 min)

Teacher: Good afternoon! I ask everyone to sit down. I congratulate you on another wonderful day. And we continue to create magic in chemistry lessons.

II.Motivation for learning activities (1 min)

Teacher: Today we have an unusual lesson. It will take the form of a game. The grade of your work at the end of the lesson will be the higher, the more points you score. The number of tasks and their type are selected in such a way that you can earn more than 40 points for completing the work. You will receive an assessment according to the conversion schemes that are on your desks.

ANSWER FORM
TASKS	Number of points scored
1. "Attention, question!" (7 points)
2. "Flower-seven-flower". (7 points)
3. Tic-tac-toe. (3 points)
4. "Young chemists and chemists." (15 points)
5. "Undress me." (4 points)
6. "Associations". (9 points)
7. "I'm a fan of fiction." (7 points)
8. "Parade of chemical elements." (3 points)
9. "Logical circles". (6 points)
10. "Pyramid". (3 points)
11. Competition "Terms". (12 min)
12. Competition "Last Chance" (10 min)

III.Control and correction of knowledge

1. Attention, question! (10 minutes)

Teacher: Describe the etymology of the names of chemical elements.

Student: The names of the elements have different etymologies. They come from:

names of countries and continents - for example, the name ruthenium comes from the Latin name of Russia, and the names of europium and americium come from the names of the continents: Europe and America;

surnames of prominent chemists - for example: mendelevium, nobelium, rutherfordium;

the names of the planets - for example: uranium, neptunium, plutonium;

river names - for example, rhenium.

All known elements have symbols. The symbolic designation of the elements was proposed in 1814 by J. J. Berzelius. Previously, various abbreviations for elements and compounds were also used. One of these types of symbols were graphic symbols.

Teacher: What do we know from the history of the development of the language of chemistry?

Student: Back in the Middle Ages, during the days of alchemy, various signs were used to designate substances, mainly metals. After all, the main goal of alchemists was to obtain gold from various metals. Therefore, each of them used their own notation. In the 19th century there was a need to use symbolism understandable to all scientists. And one of the first such symbols was proposed by John Dalton. But his notation was inconvenient to use.

Teacher: Tell us about the system of designation of chemical elements by Y.Ya. Berzelius

Student: The modern system of chemical signs was proposed at the beginning of the 19th century. Swedish chemist Jöns Jakob Berzelius. The scientist suggested designating chemical elements by the first letter of their Latin name. In those days, all scientific articles were printed in Latin, it was generally accepted and understood by all scientists. For example, the chemical element oxygen (in Latin Oxygenium) received the designation O. And the chemical element hydrogen (Hydrogenium) - H. If the names of several elements began with the same letter, then the second or one of the subsequent letters of the name was indicated in the element symbol. For example, mercury (Hydrargyrum) is designated Hg. Please note that the first letter of the sign of a chemical element is always capitalized, if there is a second letter, then it is lowercase. It is necessary to memorize not only the names of the elements and their symbols, but also the pronunciation, i.e. how these characters are read. There are no specific rules for pronouncing the signs of chemical elements. They must be learned by heart. The signs of some chemical elements are pronounced in the same way as the corresponding letter: oxygen - "o", sulfur - "es", phosphorus - "pe", nitrogen - "en", carbon - "ce". The signs of other elements are pronounced in the same way as the elements themselves are called: “sodium”, “potassium”, “chlorine”, “fluorine”. The pronunciation of some signs corresponds to their Latin name: silicon - "silicium", mercury - "hydrargyrum", copper - "cuprum", iron - "ferrum".

Teacher: What is the meaning of the signs of chemical elements?

Student: The sign of a chemical element has several meanings. First, it refers to all the atoms of a given element. Secondly, the sign of a chemical element can designate one or more atoms of a given element. For example, the notation O can mean: "the chemical element oxygen" or "one oxygen atom".

To designate several atoms of a given chemical element, you need to put a number in front of its sign corresponding to the number of atoms. For example, the notation 3N means "three nitrogen atoms". The number in front of the sign of a chemical element is called the coefficient.

Student: Attempts to streamline the ancient chemical signs continued until the end of the 18th century. At the beginning of the 19th century, the English chemist J. Dalton proposed to designate the atoms of chemical elements with circles, inside which were placed dots, dashes, the initial letters of the English names of metals, etc. Dalton's chemical signs gained some distribution in Great Britain and Western Europe, but were soon supplanted by purely alphabetic signs that the Swedish chemist J. Ya. Berzelius proposed in 1814. The principles he expressed for compiling chemical signs have retained their force to this day. In Russia, the first printed report on the chemical signs of Berzelius was made in 1824 by the Moscow physician I. Ya. Zatsepin.

Teacher: What are the design principles?

Student: Modern symbols for chemical elements consist of the first letter or of the first and one of the following letters of the Latin name of the elements. However, only the first letter is capitalized. For example, H is hydrogen (lat. Hydrogenium), N is nitrogen (lat. Nitrogenium), Ca is calcium (lat. Calcium), Pt is platinum (lat. Platinum), etc. For newly discovered transuranic elements that have not yet have received an IUPAC-approved name, use three-letter designations, meaning a numeral - a serial number. For example, Uut is ununtrium (lat. Ununtrium, 113), Uuh is unungexium (lat. Ununhexium, 116). Hydrogen isotopes have special symbols and names: H - protium 1H, D - deuterium 2H, T - tritium 3H. To designate isobars and isotopes, the symbol of a chemical element is preceded by a mass number at the top (for example, 14N), and at the bottom left is the ordinal number of the element (atomic number) (for example, 64Gd). In the case when the mass number and serial number are not indicated in the chemical formulas and chemical equations, each chemical sign expresses the average relative atomic mass of its isotopes in the earth's crust. To indicate a charged atom, the charge of the ion (eg Ca2+) is indicated at the top right. At the bottom right, the number of atoms of a given element in a real or conditional molecule (eg, N2 or Fe2O3) is indicated. Free radicals are indicated by a dot on the right (eg Cl·).

Student: Chemists of the ancient world and the Middle Ages used symbolic images, letter abbreviations, and combinations of both to designate substances, chemical operations and devices. The seven metals of antiquity were depicted as astronomical signs of the seven heavenly bodies: the Sun (☽, silver), Jupiter (♃, tin), Venus (♀, copper), Saturn (♄, lead), Mercury (☿, mercury) , Mars (♁ , iron). The metals discovered in the 15th-18th centuries - bismuth, zinc, cobalt - were designated by the first letters of their names. The sign of wine spirit (lat. spiritus vini) is made up of the letters S and V. The signs of strong vodka (lat. aqua fortis, nitric acid) and golden vodka (lat. aqua regis, aqua regia, a mixture of hydrochloric and nitric acids) are made up of the sign of water Ñ ​​and capital letters F and R, respectively. The sign of glass (lat. vitrum) is formed from two letters V - straight and inverted.

Teacher: Tell us about international and national symbols.

Student: The symbols given in the Periodic Table of the Elements are international, but along with them, in some countries, designations derived from the national names of the elements are commonly used. For example, in France, Az (Azote), Gl (Glucinium), and Tu (Tungstène) may be used instead of nitrogen N, beryllium Be, and tungsten W. In the United States, Cb (Columbium) is often used instead of Nb for niobium. China uses its own version of chemical signs based on Chinese characters. Most of the symbols were invented in the 19th and 20th centuries. Symbols for metals (except mercury) use a radical or ("gold", metal in general), for non-metals that are solid under normal conditions - a radical ("stone"), for liquids - ("water"), for gases - ("steam") . For example, the symbol for molybdenum consists of a radical and a phonetic that specifies the pronunciation of mu4.

Physical education (1 min)

2. The game "Flower-Semitsvetik" (7 points)(2 minutes.)

Inscribe in each petal of the seven-color flower physical bodies or substances (according to options) that you need to select from a specific list.

Nail, zinc, vase, hammer, iron, salt, spoon, magnesium, gold, water, ice floe, apple, pencil, glass.

Physical bodies Substances

Answers:

Body: nail, vase, hammer, spoon, ice floe, apple, pencil.

Substances: zinc, iron, salt, magnesium, gold, water, glass.

3. Tic-tac-toe game (3 points) (1 min)

Find the winning path in the tables:

Ioption- homogeneous mixtures;

IIoption- inhomogeneous mixtures.

Answer:

Top line - homogeneous mixtures;

The bottom line is heterogeneous mixtures.

4. Competition "Young chemists" (15 points, 1 point for each correct answer) (2 min)

Which of the teams will name the safety rules in the chemistry classroom more.

5. Competition "Undress me" (4 points), 1 point for the correct answer) (3 min)

Match the mixture with the method by which it can be separated into pure substances.

Answer:

Ioption

IIoption

6. Competition"Associations".(9 points)(2 minutes)

Competitors are asked to name laboratory equipment that, by function, appearance or name, is associated with the object depicted in the figure;

7. Competition "I'm a fan of fiction" (7 points, 1 point per element). (1 min)

Name as many chemical elements as possible using the letters of the term "tungsten".

Answer: vanadium, osmium, lithium, francium, rhodium, aluminum, magnesium.

8. Competition "Parade of chemical elements" (3 points). (1 min)

Fill in the table.

Answer:

10 . Competition "Pyramid" (3 points) (2 min)

Make a pyramid of chemical elements according to their atomic masses.

Answer:

11. Competition "Terms". (12 points, 1 point for correct answer) (2 min)

The teacher dictates the names of chemical elements, the students write them down on the blackboard.

Answer:

N, Na, Ba, Ca, H, O, C, Al, Mg, K, Cl, F.

12. Competition "Last Chance" (10 points, 1 point for the correct answer) (2 min)

Teams take turns answering questions without repeating. The one with the last answer wins. Translate from chemical language into common language the following expressions:

Not everything is aurum that glitters. (Not all that glitters is gold.)

White like calcium carbonate. (White as chalk).

Ferrum character. (Iron character).

The word is argentum, and silence is aurum. (Word is silver, silence is gold).

A lot of ash two o flowed away. (A lot of water has flowed under the bridge).

Which element is always happy. (Radon).

Which gas claims to be not it? (Neon).

Which element "revolves" around the sun? (Uranus).

Which element is the real "giant" (Titanium).

What element is named after Russia? (Ruthenium).

IV. Psummarizing. (1 min.)

Teacher: All this time, for twelve lessons, we have been trying to open the symbolic door and enter an interesting country called chemistry. We were able to open it a little and see what was behind it. It is interesting there, there is a lot of unknown that attracts us. Now we will decide whether you are ready for the serious tests that await us. Let's find out if you have enough knowledge for this, whether you have mastered these topics well. Yes, not just learned, but which of you did better.

(Announcement of grades by points)

v.Homework(1 min)

§12, #1-4 p.44. Creative task: make a chemical crossword puzzle.

VI.Reflection(1 min)

Today I found out...

it was difficult…

I realized that...

I learned…

It was interesting to know that...

surprised me...

Chemistry, like any science, requires precision. The data representation system in this field of knowledge has been developed for centuries, and the current standard is an optimized structure that contains all the necessary information for further theoretical work with each specific element.

When writing formulas and equations, it is extremely inconvenient to use integers, and today one or two letters are used for this purpose - the chemical symbols of elements.

Story

In the ancient world, as well as in the Middle Ages, scientists used symbolic images to denote various elements, but these signs were not standardized. It was not until the 13th century that attempts were made to systematize the symbols of substances and elements, and from the 15th century, newly discovered metals began to be designated by the first letters of their names. A similar naming strategy is used in chemistry to this day.

The current state of the naming system

To date, more than one hundred and twenty chemical elements are known, some of which are extremely problematic to find in nature. It is not surprising that even in the middle of the 19th century, science knew about the existence of only 63 of them, and there was neither a single naming system nor an integral system for presenting chemical data.

The last problem was solved in the second half of the same century by the Russian scientist D. I. Mendeleev, relying on the unsuccessful attempts of his predecessors. The naming process continues today - there are several elements with numbers from 119 and above, conventionally indicated in the table by the Latin abbreviation of their serial number. The pronunciation of the symbols of chemical elements of this category is carried out according to the Latin rules for reading numerals: 119 - ununenny (lit. "one hundred and nineteenth"), 120 - unbinilium ("one hundred and twentieth") and so on.

Most of the elements have their own names, derived from Latin, Greek, Arabic, German roots, in some cases reflecting the objective characteristics of substances, and in others acting as unmotivated symbols.

Etymology of some elements

As mentioned above, some names and symbols of chemical elements are based on objectively observable signs.

The name of phosphorus, glowing in the dark, comes from the Greek phrase "bring light". When translated into Russian, quite a lot of "speaking" names are found: chlorine - "greenish", bromine - "bad smelling", rubidium - "dark red", indium - "indigo color". Since the chemical symbols of the elements are given in Latin letters, the direct connection of the name with the substance for a Russian speaker usually goes unnoticed.

There are also more subtle naming associations. So, the name of selenium comes from the Greek word meaning "Moon". This happened because in nature this element is a satellite of tellurium, whose name in the same Greek means "Earth".

Niobium is named similarly. According to Greek mythology, Niobe is the daughter of Tantalus. The chemical element tantalum was discovered earlier and is similar in its properties to niobium - thus, the logical connection "father-daughter" was projected onto the "relationship" of chemical elements.

Moreover, tantalum got its name in honor of the famous mythological character not by chance. The fact is that obtaining this element in its pure form was fraught with great difficulties, due to which scientists turned to the phraseological unit “Tantalum flour”.

Another curious historical fact is that the name of platinum literally translates as "silver", i.e. something similar, but not as valuable as silver. The reason is that this metal melts much more difficult than silver, and therefore for a long time it was not used and was not of particular value.

General principle of naming elements

When looking at the periodic table, the first thing that catches your eye is the names and symbols of the chemical elements. It is always one or two Latin letters, the first of which is capital. The choice of letters is due to the Latin name of the element. Despite the fact that the roots of words come from ancient Greek, and from Latin, and from other languages, according to the naming standard, Latin endings are added to them.

It is interesting that most of the characters will be intuitively understandable to a native Russian speaker: a student easily remembers aluminum, zinc, calcium or magnesium from the first time. The situation is more complicated with those names that differ in the Russian and Latin versions. The student may not immediately remember that silicon is silicium, and mercury is hydrargyrum. Nevertheless, you will have to remember this - the graphic representation of each element is focused on the Latin name of the substance, which will appear in chemical formulas and reactions as Si and Hg, respectively.

To remember such names, it is useful for students to perform exercises like: "Make a correspondence between the symbol of a chemical element and its name."

Other ways of naming

The names of some elements originated from the Arabic language and were "stylized" in Latin. For example, sodium takes its name from a root stem meaning "bubbling substance". Arabic roots can also be traced to the names of potassium and zirconium.

The German language also had its influence. From it come the names of such elements as manganese, cobalt, nickel, zinc, tungsten. The logical connection is not always obvious: for example, nickel is an abbreviation for the word meaning "copper devil".

In rare cases, the names were translated into Russian in the form of tracing paper: hydrogenium (literally "giving birth to water") turned into hydrogen, and carboneum into carbon.

Names and toponyms

More than a dozen elements are named after various scientists, including Albert Einstein, Dmitri Mendeleev, Enrico Fermi, Ernest Rutherford, Niels Bohr, Marie Curie and others.

Some names come from other proper names: the names of cities, states, countries. For example: moscovium, dubnium, europium, tennessine. Not all toponyms will seem familiar to a native speaker of the Russian language: it is unlikely that a person without cultural training will recognize the self-name of Japan in the word nihonium - Nihon (literally: the Land of the Rising Sun), and in hafnia - the Latin version of Copenhagen. Finding out even the name of your native country in the word ruthenium is not an easy task. Nevertheless, Russia in Latin is called Ruthenia, and it is in her honor that the 44th chemical element is named.

The names of cosmic bodies also appear in the periodic table: the planets Uranus, Neptune, Pluto, Ceres. In addition to the names of the characters of ancient Greek mythology (Tantalum, Niobium), there are also Scandinavian ones: thorium, vanadium.

Periodic table

In the periodic table familiar to us today, bearing the name of Dmitry Ivanovich Mendeleev, the elements are presented in series and periods. In each cell, a chemical element is indicated by a chemical symbol, next to which other data are presented: its full name, serial number, distribution of electrons over layers, relative atomic mass. Each cell has its own color, which depends on whether the s-, p-, d- or f- element is highlighted.

Recording principles

When writing isotopes and isobars, a mass number is placed on the top left of the element symbol - the total number of protons and neutrons in the nucleus. In this case, the atomic number is placed at the bottom left, which is the number of protons.

The charge of the ion is written on the top right, and the number of atoms is indicated on the same side below. Symbols for chemical elements always begin with a capital letter.

National spelling options

The Asia-Pacific region has its own spellings of the symbols of chemical elements, based on local writing methods. The Chinese notation system uses radical signs followed by characters in their phonetic meaning. Symbols of metals are preceded by the sign "metal" or "gold", gases - by the radical "steam", non-metals - by the hieroglyph "stone".

In European countries, there are also situations when the signs of elements during recording differ from those recorded in international tables. For example, in France, nitrogen, tungsten and beryllium have their own names in the national language and are denoted by the corresponding symbols.

Finally

Studying at school or even a higher educational institution, memorizing the contents of the entire periodic table is not required at all. In memory, you should keep the chemical symbols of the elements that are most often found in formulas and equations, and look at the little-used ones from time to time on the Internet or a textbook.

However, in order to avoid errors and confusion, it is necessary to know how the data is structured in the table, in which source to find the required data, and to clearly remember which element names differ in Russian and Latin versions. Otherwise, you can accidentally mistake Mg for manganese, and N for sodium.

To get practice at the initial stage, do the exercises. For example, specify the symbols for chemical elements for a randomly selected sequence of names from the periodic table. As you gain experience, everything will fall into place and the question of remembering this basic information will disappear by itself.

In nature, there are a lot of repeating sequences:

• seasons;
• Times of Day;
• days of the week…

In the middle of the 19th century, D.I. Mendeleev noticed that the chemical properties of elements also have a certain sequence (they say that this idea came to him in a dream). The result of the miraculous dreams of the scientist was the Periodic Table of Chemical Elements, in which D.I. Mendeleev arranged the chemical elements in order of increasing atomic mass. In the modern table, the chemical elements are arranged in ascending order of the atomic number of the element (the number of protons in the nucleus of an atom).

The atomic number is shown above the symbol of a chemical element, below the symbol is its atomic mass (the sum of protons and neutrons). Note that the atomic mass of some elements is a non-integer! Remember isotopes! Atomic mass is the weighted average of all the isotopes of an element that occur naturally under natural conditions.

Below the table are the lanthanides and actinides.

Metals, non-metals, metalloids

They are located in the Periodic Table to the left of the stepped diagonal line that starts with Boron (B) and ends with polonium (Po) (the exceptions are germanium (Ge) and antimony (Sb). It is easy to see that metals occupy most of the Periodic Table. The main properties of metals : solid (except mercury); shiny; good electrical and thermal conductors; ductile; malleable; easily donate electrons.

The elements to the right of the stepped diagonal B-Po are called non-metals. The properties of non-metals are directly opposite to the properties of metals: poor conductors of heat and electricity; fragile; non-forged; non-plastic; usually accept electrons.

Metalloids

Between metals and non-metals are semimetals(metalloids). They are characterized by the properties of both metals and non-metals. Semimetals have found their main industrial application in the production of semiconductors, without which no modern microcircuit or microprocessor is inconceivable.

Periods and groups

As mentioned above, the periodic table consists of seven periods. In each period, the atomic numbers of the elements increase from left to right.

The properties of elements in periods change sequentially: so sodium (Na) and magnesium (Mg), which are at the beginning of the third period, give up electrons (Na gives up one electron: 1s 2 2s 2 2p 6 3s 1; Mg gives up two electrons: 1s 2 2s 2 2p 6 3s 2). But chlorine (Cl), located at the end of the period, takes one element: 1s 2 2s 2 2p 6 3s 2 3p 5.

In groups, on the contrary, all elements have the same properties. For example, in the IA(1) group, all elements from lithium (Li) to francium (Fr) donate one electron. And all elements of group VIIA(17) take one element.

Some groups are so important that they have been given special names. These groups are discussed below.

Group IA(1). The atoms of the elements of this group have only one electron in the outer electron layer, so they easily donate one electron.

The most important alkali metals are sodium (Na) and potassium (K), since they play an important role in the process of human life and are part of salts.

Electronic configurations:

• Li- 1s 2 2s 1 ;
• Na- 1s 2 2s 2 2p 6 3s 1 ;
• K- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1

Group IIA(2). The atoms of the elements of this group have two electrons in the outer electron layer, which also give up during chemical reactions. The most important element is calcium (Ca) - the basis of bones and teeth.

Electronic configurations:

• Be- 1s 2 2s 2 ;
• mg- 1s 2 2s 2 2p 6 3s 2 ;
• Ca- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2

Group VIIA(17). Atoms of the elements of this group usually receive one electron each, because. on the outer electronic layer there are five elements each, and one electron is just missing to the "complete set".

The most famous elements of this group are: chlorine (Cl) - is part of salt and bleach; iodine (I) is an element that plays an important role in the activity of the human thyroid gland.

Electronic configuration:

• F- 1s 2 2s 2 2p 5 ;
• Cl- 1s 2 2s 2 2p 6 3s 2 3p 5 ;
• Br- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5

Group VIII(18). Atoms of the elements of this group have a fully "staffed" outer electron layer. Therefore, they "do not need" to accept electrons. And they don't want to give them away. Hence - the elements of this group are very "reluctant" to enter into chemical reactions. For a long time it was believed that they do not react at all (hence the name "inert", i.e. "inactive"). But chemist Neil Barlett discovered that some of these gases, under certain conditions, can still react with other elements.

Electronic configurations:

• Ne- 1s 2 2s 2 2p 6 ;
• Ar- 1s 2 2s 2 2p 6 3s 2 3p 6 ;
• kr- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6

Valence elements in groups

It is easy to see that within each group, the elements are similar to each other in their valence electrons (electrons of s and p orbitals located on the outer energy level).

Alkali metals have 1 valence electron each:

• Li- 1s 2 2s 1 ;
• Na- 1s 2 2s 2 2p 6 3s 1 ;
• K- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1

Alkaline earth metals have 2 valence electrons:

• Be- 1s 2 2s 2 ;
• mg- 1s 2 2s 2 2p 6 3s 2 ;
• Ca- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2

Halogens have 7 valence electrons:

• F- 1s 2 2s 2 2p 5 ;
• Cl- 1s 2 2s 2 2p 6 3s 2 3p 5 ;
• Br- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5

Inert gases have 8 valence electrons:

• Ne- 1s 2 2s 2 2p 6 ;
• Ar- 1s 2 2s 2 2p 6 3s 2 3p 6 ;
• kr- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6

For more information, see the article Valency and the Table of electronic configurations of atoms of chemical elements by periods.

Let us now turn our attention to the elements located in groups with symbols AT. They are located in the center of the periodic table and are called transition metals.

A distinctive feature of these elements is the presence of electrons in atoms that fill d-orbitals:

1. sc- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 1 ;
2. Ti- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2

Separate from the main table are located lanthanides and actinides are the so-called internal transition metals. In the atoms of these elements, electrons fill f-orbitals:

1. Ce- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 4d 10 5s 2 5p 6 4f 1 5d 1 6s 2 ;
2. Th- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 4d 10 5s 2 5p 6 4f 14 5d 10 6s 2 6p 6 6d 2 7s 2