As a result of studying this chapter, the student should: know

• basic concepts and specifics of the chemical picture of the world;
• the role of alchemy in the development of chemistry as a science;
• historical stages in the development of chemistry as a science;
• the leading principles of the doctrine of the composition and structure of substances;
• the main factors in the course of chemical reactions and the conditions for their control;
• basic principles of evolutionary chemistry and its role in explaining biogenesis; be able to
• reveal the role of the physics of the microworld for understanding the foundations of chemical science;
• conduct a comparative analysis of the main stages in the development of chemistry;
• argued to show the role of chemistry to explain the structural levels of the systemic organization of matter;

own

• the skills of acquiring and applying knowledge to form a chemical picture of the world;
• skills in using the conceptual apparatus of chemistry to characterize chemical processes.

Historical stages in the development of chemical science

There are many definitions of chemistry that characterize it as a science:

• about chemical elements and their compounds;
• substances, their composition and structure;
• processes of qualitative transformation of substances;
• chemical reactions, as well as the laws and regularities that these reactions obey.

Obviously, each of them reflects only one of the aspects of extensive chemical knowledge, and chemistry itself acts as a highly ordered, constantly developing system of knowledge. Here is a definition from a classic textbook: “Chemistry is the science of the transformations of substances. It studies the composition and structure of substances, the dependence of the properties of substances on their composition and structure, the conditions and ways of transformation of one substance into another.

Chemistry is the science of the transformations of substances.

The most important distinguishing feature of chemistry is that it is in many ways independently forms subject of research, creating substances that did not exist in nature. Like no other science, chemistry simultaneously acts both as a science and as a production. Since modern chemistry solves its problems at the atomic-molecular level, it is closely connected with physics, biology, as well as such sciences as geology, mineralogy, etc. The border areas between these sciences are studied by quantum chemistry, chemical physics, physical chemistry, geochemistry, biochemistry and etc.

More than 200 years ago, the great M. V. Lomonosov spoke at a public meeting of the St. Petersburg Academy of Sciences. in the report "A word about the benefits of chemistry" we read prophetic lines: “Chemistry spreads its hands wide in human affairs ... Wherever we look, wherever we look, everywhere we turn before our eyes the successes of its diligence.” Chemistry began to spread its "diligence" even in Egypt - the advanced country of the Ancient World. Such branches of production as metallurgy, ceramics, glass making, dyeing, perfumery, cosmetics reached significant development there long before our era.

Let's compare the name of the science of chemistry in different languages:

All these words contain the root "chem" or " chem”, which is consonant with the words of the ancient Greek language: “himos” or “hyumos” meant “juice”. This name is found in manuscripts containing information on medicine and pharmacy.

There are other points of view. According to Plutarch, the term "chemistry" comes from one of the ancient names of Egypt - Hemi ("drawing earth"). In its original sense, the term meant "Egyptian art". Chemistry as the science of substances and their interactions was considered in Egypt a divine science and was entirely in the hands of the priests.

One of the oldest branches of chemistry is metallurgy. For 4-3 thousand years BC. began to smelt copper from ores, and later to produce an alloy of copper and tin (bronze). In the II millennium BC. learned how to get iron from ores by raw-blowing process. For 1600 years BC. they began to use natural indigo dye for dyeing fabrics, and a little later - purple and alizarin, as well as prepare vinegar, medicines from plant materials and other products, the production of which is associated with chemical processes.

In the Arab East in the V-VI centuries. the term "alchemy" appears by adding the particle "al-" to the Greco-Egyptian "chemistry". The goal of the alchemists was to create a "philosopher's stone" capable of turning all base metals into gold. It was based on a practical order: gold

in Europe was necessary for the development of trade, and there were few known gold deposits.

Fact from the history of science

The oldest discovered chemical texts are now considered ancient Egyptian "Ebers Papyrus"(named after the German Egyptologist who found it) - a collection of recipes for the manufacture of medicines of the 16th century. BC, as well as the “Brugsch Papyrus” found in Memphis with pharmaceutical prescriptions (XIV century BC).

The prerequisites for the formation of chemistry as an independent scientific discipline were formed gradually during the 17th - the first half of the 18th century. At the same time, despite the variety of empirical material, in this science, until the discovery in 1869 of the periodic system of chemical elements by D. I. Mendeleev (1834-1907), there was no general theory that could be used to explain the accumulated actual material.

Attempts to periodize chemical knowledge were made as early as the 19th century. According to the German scientist G. Kopp - the author of a four-volume monograph "History of Chemistry"(1843-1847), the development of chemistry took place under the influence of a certain guiding idea. He identified five stages:

• the era of the accumulation of empirical knowledge without attempts to theoretically explain them (from ancient times to the 4th century AD);
• alchemical period (IV - beginning of the 16th century);
• period of iatrochemistry, i.e. "Chemistry of Healing" (second quarter of the 16th - mid-17th centuries);
• the period of creation and dominance of the first chemical theory - the theory of phlogiston (mid-17th - third quarter of the 18th century);
• period of quantitative research (last quarter of the 18th - 1840s) 1 .

However, according to modern concepts, this classification refers to those stages when chemical science has not yet been constituted as a systemic theoretical knowledge.

Domestic historians of chemistry distinguish four conceptual levels, which are based on a way to solve the central problem of chemistry as a science and as a production (Fig. 13.1).

First conceptual level - study of the structure of a chemical substance. At this level, various properties and transformations of substances were studied depending on their chemical composition.

Rice. 13.1.

It is easy to see the analogy of this concept with the physical concept of atomism. Both physicists and chemists sought to find the original basis by which it would be possible to explain the properties of all simple and complex substances. This concept was formulated quite late - in 1860, at the first International Congress of Chemists in Karlsruhe, Germany. The chemists proceeded from the fact that All substances are made up of molecules and all molecules, in turn are made up of atoms. Both atoms and molecules are in continuous motion, while atoms are the smallest, and then indivisible parts of molecules 1.

The significance of the Congress was clearly expressed by D. I. Mendeleev: G. A.), chemists of all countries accepted the beginning of the unitary system; now it would be a great inconsistency, recognizing the beginning, not recognizing its consequences.

Second conceptual level - study of the structure of chemicals, identification of a specific method of interaction of elements in the composition of specific chemicals. It was found that the properties of substances depend not only on their constituent chemical elements, but also on the relationship and interaction of these elements in the course of a chemical reaction. So, diamond and coal have different properties precisely because of the difference in structures, although their chemical composition is similar.

Third conceptual level Chemistry is generated by the needs of increasing the productivity of chemical industries and explores the internal mechanisms and external conditions for the occurrence of chemical processes: temperature, pressure, reaction rate, etc.

Fourth conceptual level - level of evolutionary chemistry. At this level, the nature of the reagents involved in chemical reactions, the specifics of the action of catalysts, which significantly accelerate their rate, are studied in more depth. It is at this level that the process of origin is comprehended. alive matter from inert matter.

• Glinka II. L. General chemistry. 2b ed. L .: Chemistry: Leningrad branch, 1987. S. 13.
• Cit. Quoted from: Koltun M. World of Chemistry. M .: Children's literature, 1988. S. 7.
• Mendeleev D. I. Op. in 25 vols. L. - M.: Publishing House of the Academy of Sciences of the USSR, 1949. T. 15. S. 171-172.

Topic: Chemistry is a natural science. Chemistry in the environment.

Target: to interest students in a new subject for them - chemistry;

reveal the role of chemistry in human life; educate children

responsible attitude towards nature.

Tasks: 1. consider the meaning of the word chemistry, as one of the natural

2. determine the meaning and relationship of chemistry with others

3. find out what effect chemistry has on a person and

Equipment and materials:"Chemistry in the Guinness Book of Records";

Chemical market: related articles; scientists' statement about

chemistry; mineral water; bread, iodine; shampoo, tablets, toothpaste

paste, varnish, etc.

Terms and concepts: chemistry; substances: simple and complex; chemical

element; atom, molecule.

Lesson type: learning new material.

During the classes

I. organizational stage.

The bell rang

The lesson has begun. We came here to study

Don't be lazy, but work hard.

We work diligently

We listen carefully.

Hello guys

II. Actualization and motivation of educational activities. Today, you start studying a new subject - chemistry.

You already got acquainted with some concepts of chemistry at the lessons of natural history. . Give examples

(Body, substance, chemical element, molecule, atom).What substances do you use at home? (water, sugar, salt, vinegar, soda, alcohol, etc.) What do you associate the word chemistry with??(Food, clothing, water, cosmetics, home). We cannot imagine our life without such means: as toothpaste, shampoo, powders, hygiene products that keep our body and clothes clean and tidy. The objects that surround us consist of substances: simple or complex, and they, in turn, from the chemical elements of one or many. Our body also includes almost the entire periodic table, for example: the blood contains the chemical element Ferum (Iron), which, when combined with Oxygen, is part of hemoglobin, forming red blood cells - erythrocytes, the stomach contains Hydrochloric acid, which contributes to a faster the breakdown of food, our body consists of 70% water, without which human life is not possible .. We will get acquainted with this and other substances throughout the course of chemistry.

Of course, in chemistry, as in any science, except for the entertaining, there will also be difficult ones. But it is difficult and interesting - this is exactly what a thinking person needs, so that our mind is not in idleness and laziness, but constantly works and works. Therefore, the theme of the first lesson is an introduction to chemistry as one of the natural sciences.

We write in a notebook:

Classwork.

Topic: Chemistry is a natural science. Chemistry in the environment.

III. Learning new material.

Epigraph:

O you happy sciences!

Stretch out your hands diligently

And look to the farthest places.

Pass the earth and the abyss,

And the steppes, and the deep forest,

And the very height of heaven.

Everywhere explore all the time,

What is great and beautiful

What the world has not yet seen ... ..

In the bowels of the earth you, Chemistry,

Penetrated the sharpness of the gaze,

And what does Russia contain in it,

Open the treasure treasures...

M.V. Lomonosov "Ode of Gratitude"

Fiz minute

Handles pulled to the sky (pull up)

The spine was stretched (spread apart)

We all had time to rest (shake your hands)

And sat down at the desk again.

The word "chemistry" comes from the word "himi" or "huma" from ancient Egypt, as black earth, that is, black as earth, which deals with various minerals.

In everyday life, you often encounter chemical reactions. For example:

An experience: 1. Drop a drop of iodine on bread, potatoes - blue color, which is a qualitative reaction to starch. You can test yourself on other objects for their starch content.

2. Open a bottle of carbonated water. There is a decomposition reaction of carbonic or carbonate acid into carbon dioxide and water.

H2CO3 CO2 + H2O

3. Acetic acid + soda carbon dioxide + sodium acetate. Grandmothers and mothers bake pies for you. In order for the dough to be soft and fluffy, soda slaked with vinegar is added to it.

All these phenomena are explained by chemistry.

Some interesting facts related to chemistry.:

Why is the bashful mimosa called that?

The bashful mimosa plant is known for the fact that its leaves fold when someone touches it, and after a while they straighten again. This mechanism is due to the fact that specific areas on the plant stem, when externally stimulated, release chemicals, including potassium ions. They act on the cells of the leaves, from which the outflow of water begins. Because of this, the internal pressure in the cells drops, and, as a result, the petiole and petals on the leaves curl up, and this effect can be transmitted along the chain to other leaves.

Use of toothpaste: removes plaque from tea on the cup, as it contains soda, which cleans it.

Inquiry into the death of Emperor Napoleon .

The captured Napoleon, accompanied by his escort in 1815, arrived on the island of St. Helena, in good enviable health, but in 1821 he died. He was diagnosed with stomach cancer. Locks of the deceased's hair were cut and distributed to the emperor's devoted supporters. So they have reached our time. In 1961, studies of Napoleon's hair for arsenic were published. It turned out that the hair contained an increased content of arsenic and antimony, which were gradually mixed into food, which caused gradual poisoning. Thus, chemistry, a century and a half after death, helped to solve some crimes.

Working with the textbook 5 find and write down the definition of the concept of chemistry.

Chemistry is the science of substances and their transformations. As a science, it is exact and experimental, since it is accompanied by experiments, or an experiment, at the same time, the necessary calculations are carried out and after that only conclusions are drawn.

Chemists study the variety of substances and their properties; phenomena that occur with substances; composition of substances; structure; properties; transformation conditions; possibilities of use.

Distribution of substances in nature. Consider Figure 1. What conclusion can be drawn from this.(Substances exist not only on Earth, but also outside it.) But all substances are made up of chemical elements. Some information about chemical elements and substances is listed in the Guinness Book of Records: for example

The most common element: in the lithosphere - oxygen (47%), in the atmosphere - Nitrogen (78%), outside the Earth - Hydrogen (90%), the most expensive - California.

The most malleable metal - Gold from 1 g can be drawn into a wire 2.4 km long (2,400 m), the hardest - chromium, the most warm - and electrically conductive - silver. The most expensive substance is interferon: one millionth microgram of a pure drug costs $10.

Chemistry is closely related to other natural sciences. What natural sciences can you name?

Consider diagram 1. 6

Ecology Agriculture Agrochemistry

Physchemistry

Physics Chemistry Biology Biochemistry Medicine

Mathematics Geography Astronomy Cosmochemistry

pharmaceutical chemistry

But besides this, chemistry itself can also be classified:

Chemistry classification

Inorganic Organic Analytical

general chemistry

All this will be studied throughout the school chemistry course.

Man must exist in harmony with nature, but at the same time he himself destroys it. Each of you can both protect and pollute nature. Paper, polyethylene, plastic - you need to throw only in special bins, and not scatter where you are, as they do not decompose. When burning plastic and polyethylene, very toxic substances are released that affect humans. In the autumn, when the leaves are burned, toxic substances are also formed, although they can be piled up for the rotting process, and then used as biological fertilizers. The use of household chemicals leads to water pollution. Therefore, the preservation of nature for future generations depends on the careful attitude of each of us to it, on the level of culture, chemical knowledge.

IV. Generalization and systematization of knowledge.

1. Continue the definition:

Chemistry is……………………………………………………………………..

2. Choose the correct statements:

a. Chemistry - Humanities

b. Chemistry is a natural science.

in. Knowledge of chemistry is necessary only for biologists.

d. Chemicals are found only on Earth.

e. For life, breathing, a person needs carbon dioxide.

e. Life on the Planet is not possible without oxygen.

3. From the given sciences that are interconnected with chemistry, select those related to definitions.

Biochemistry, Ecology, Physical chemistry, Geology, Agrochemistry

1. Chemical processes occurring in the human body are studied by science - Biochemistry.

2. The science of environmental protection is called Ecology

3. Exploration of minerals - Geology

4. The transformation of some substances into others is accompanied by the absorption or release of heat, the science of Physical Chemistry studies

5. The study of the effect of fertilizers on soil and plants is the science of Agrochemistry.

4. What influence does Chemistry have on nature.

V. Summing up the lesson.

From the material presented it follows that Chemistry is the science of substances and their transformations. In the modern world, a person cannot imagine his life without chemicals. There is practically no industry where chemical knowledge would not be needed. The impact of chemistry and chemicals on humans and the environment, both positive and negative. Each of us can save a piece of nature, such as it is. Protect the environment.

VI. Homework.

2. Answer the questions on p. ten . 1- orally, 2-4 in writing.

3. Prepare reports on the topic: "The history of the development of chemistry as a science"

Science is one of the most important areas of human activity at the present stage of development of world civilization. Today there are hundreds of different disciplines: technical, social, humanitarian, natural sciences. What are they studying? How did natural science develop in the historical aspect?

Natural science is...

What is natural science? When did it originate and what directions does it consist of?

Natural science is a discipline that studies natural phenomena and phenomena that are external to the subject of research (man). The term "natural science" in Russian comes from the word "nature", which is a synonym for the word "nature".

The foundation of natural science can be considered mathematics, as well as philosophy. By and large, all modern natural sciences came out of them. At first, naturalists tried to answer all questions concerning nature and its various manifestations. Then, as the subject of research became more complex, natural science began to break up into separate disciplines, which over time became more and more isolated.

In the context of modern times, natural science is a complex of scientific disciplines about nature, taken in their close relationship.

The history of the formation of natural sciences

The development of the natural sciences took place gradually. However, human interest in natural phenomena manifested itself in antiquity.

Naturphilosophy (in fact, science) actively developed in Ancient Greece. Ancient thinkers, with the help of primitive methods of research and, at times, intuition, were able to make a number of scientific discoveries and important assumptions. Even then, natural philosophers were sure that the Earth revolves around the Sun, they could explain solar and lunar eclipses, and quite accurately measured the parameters of our planet.

In the Middle Ages, the development of natural science slowed down noticeably and was heavily dependent on the church. Many scientists at that time were persecuted for the so-called heterodoxy. All scientific research and research, in fact, came down to the interpretation and substantiation of the scriptures. Nevertheless, in the era of the Middle Ages, logic and theory developed significantly. It is also worth noting that at this time the center of natural philosophy (the direct study of natural phenomena) geographically shifted towards the Arab-Muslim region.

In Europe, the rapid development of natural science begins (resumes) only in the 17th-18th centuries. This is a time of large-scale accumulation of factual knowledge and empirical material (results of "field" observations and experiments). The natural sciences of the 18th century are also based in their research on the results of numerous geographical expeditions, voyages, and studies of newly discovered lands. In the 19th century, logic and theoretical thinking again came to the fore. At this time, scientists are actively processing all the collected facts, putting forward various theories, formulating patterns.

Thales, Eratosthenes, Pythagoras, Claudius Ptolemy, Archimedes, Galileo Galilei, Rene Descartes, Blaise Pascal, Nikola Tesla, Mikhail Lomonosov and many other famous scientists should be referred to the most outstanding naturalists in the history of world science.

The problem of classification of natural science

The basic natural sciences include: mathematics (which is also often called the "queen of sciences"), chemistry, physics, biology. The problem of classification of natural science has existed for a long time and worries the minds of more than a dozen scientists and theorists.

This dilemma was best handled by Friedrich Engels, a German philosopher and scientist who is better known as a close friend of Karl Marx and co-author of his most famous work called Capital. He was able to distinguish two main principles (approaches) of the typology of scientific disciplines: this is an objective approach, as well as the principle of development.

The most detailed was offered by the Soviet methodologist Bonifatiy Kedrov. It has not lost its relevance even today.

List of natural sciences

The whole complex of scientific disciplines is usually divided into three large groups:

• humanities (or social) sciences;
• technical;
• natural.

Nature is studied by the latter. The full list of natural sciences is presented below:

• astronomy;
• biology;
• the medicine;
• geology;
• soil science;
• physics;
• natural history;
• chemistry;
• botany;
• zoology;
• psychology.

As for mathematics, scientists do not have a common opinion as to which group of scientific disciplines it should be attributed. Some consider it a natural science, others an exact one. Some methodologists include mathematics in a separate class of so-called formal (or abstract) sciences.

Chemistry

Chemistry is a vast area of ​​natural science, the main object of study of which is matter, its properties and structure. This science also considers objects at the atomic-molecular level. It also studies chemical bonds and reactions that occur when different structural particles of a substance interact.

For the first time, the theory that all natural bodies consist of smaller (not visible to humans) elements was put forward by the ancient Greek philosopher Democritus. He suggested that every substance includes smaller particles, just as words are made up of different letters.

Modern chemistry is a complex science that includes several dozen disciplines. These are inorganic and organic chemistry, biochemistry, geochemistry, even cosmochemistry.

Physics

Physics is one of the oldest sciences on Earth. The laws discovered by it are the basis, the foundation for the entire system of disciplines of natural science.

The term "physics" was first used by Aristotle. In those distant times, it was practically identical philosophy. Physics began to turn into an independent science only in the 16th century.

Today, physics is understood as a science that studies matter, its structure and movement, as well as the general laws of nature. There are several main sections in its structure. These are classical mechanics, thermodynamics, the theory of relativity and some others.

physical geography

The demarcation between the natural and human sciences ran like a thick line through the "body" of the once unified geographical science, dividing its individual disciplines. Thus, physical geography (as opposed to economic and social) found itself in the bosom of natural science.

This science studies the geographic shell of the Earth as a whole, as well as individual natural components and systems that make up its composition. Modern physical geography consists of a number of them:

• landscape science;
• geomorphology;
• climatology;
• hydrology;
• oceanology;
• soil science and others.

Natural and Human Sciences: Unity and Differences

Humanities, natural sciences - are they as far apart as it might seem?

Of course, these disciplines differ in the object of research. The natural sciences study nature, the humanities focus their attention on man and society. The humanities cannot compete with the natural disciplines in accuracy, they are not able to mathematically prove their theories and confirm hypotheses.

On the other hand, these sciences are closely related, intertwined with each other. Especially in the 21st century. So, mathematics has long been introduced into literature and music, physics and chemistry - into art, psychology - into social geography and economics, and so on. In addition, it has long become obvious that many important discoveries are made just at the junction of several scientific disciplines, which, at first glance, have absolutely nothing in common.

Finally...

Natural science is a branch of science that studies natural phenomena, processes and phenomena. There are a huge number of such disciplines: physics, mathematics and biology, geography and astronomy.

The natural sciences, despite numerous differences in the subject and methods of research, are closely related to social and humanitarian disciplines. This connection is especially strong in the 21st century, when all the sciences converge and intertwine.

Chemistry is a natural science. Like other natural sciences, it studies a certain side of nature and natural phenomena. Unlike other natural sciences, chemistry pays close attention to matter. A substance is, for example, water, some metal, salt, a certain protein.

Many objects that surround us consist not of one, but of many substances. For example, a living organism consists of water, proteins, fats, carbohydrates and a number of other substances. Even substances that are homogeneous in appearance can be mixtures of different substances (for example, solutions).

The science of chemistry throughout history has made it possible not only to study the structure and properties of substances, but also to obtain new substances that were not previously in nature. These are, for example, various plastics, organic substances.

Chemistry, like mathematics, has its own formal language. The interactions of substances here are usually expressed through a certain record of chemical reactions, and the substances themselves are written in the form of formulas.

Chemistry explains many of the changes in nature. The main question that chemistry answers is why do some substances turn into others?

Lesson #1

Topic: Chemistry is a natural science.

Target: give the concept of chemistry as a science; show the place of chemistry among the natural sciences; to acquaint with the history of the origin of chemistry; consider the importance of chemistry in human life; learn the rules of conduct in the chemistry classroom; to acquaint with scientific methods of knowledge in chemistry; develop the logic of thinking, the ability to observe; to cultivate interest in the subject being studied, perseverance, diligence in studying the subject.

During the classes.

IClass organization.

IIUpdating of basic knowledge.

What natural sciences do you know, study?

Why are they called natural?

IIIThe message of the topic, the objectives of the lesson, the motivation of educational activities.

After reporting the topic and purpose of the lesson, the teacher poses a problematic question.

What do you think chemistry studies? (Students express their assumptions, all of them are written on the board). Then the teacher says that during the lesson we will find out which assumptions are correct.

IIILearning new material.

Before starting our lesson, we must learn the rules of conduct in the chemistry room. Look in front of you on the wall stand on which these rules are written. Every time you enter the office, you must repeat these rules, know them and strictly follow them.

(We read aloud the rules of conduct in the chemistry room.)

Rules of conduct for students in the chemistry classroom.

You can enter the chemistry room only with the permission of the teacher

In the chemistry room you need to walk with a measured step. In no case should you move sharply, as you can overturn the equipment and reagents standing on the tables

During the experimental work in the chemistry room, it is necessary to be in a dressing gown.

When conducting experimental work, you can start work only after the permission of the teacher.

When performing experiments, work calmly, without fuss. Don't push your roommate. Remember! Accuracy is the key to success!

After completing the experiments, it is necessary to put the workplace in order and wash your hands thoroughly with soap and water.

Chemistry is a natural science, the place of chemistry among the natural sciences.

The natural sciences include physical geography, astronomy, physics, biology, ecology and others. They study the objects and phenomena of nature.

Let us consider what place chemistry occupies among other sciences. It provides them with substances, materials and modern technologies. And at the same time, he uses the achievements of mathematics, physics, biology, ecology for his own further development. Therefore, chemistry is a central, fundamental science.

The boundaries between chemistry and other natural sciences are increasingly blurred. Physical chemistry and chemical physics arose at the boundary of the study of physical and chemical phenomena. Biochemistry - biological chemistry - studies the chemical composition and structure of compounds found in living organisms.

The history of the origin of chemistry.

The science of substances and their transformations originated in Egypt, the technically most advanced country of the ancient world. Egyptian priests were the first chemists. They held many hitherto unsolved chemical secrets. For example, techniques for embalming the bodies of dead pharaohs and nobles, as well as obtaining some paints.

Such branches of production as pottery, glassmaking, dyeing, perfumery, reached significant development in Egypt long before our era. Chemistry was considered a "divine" science, was entirely in the hands of the priests and was carefully hidden by them from all the uninitiated. However, some information still penetrated beyond Egypt.

Approximately in the 7th century. AD The Arabs adopted the property and methods of work of the Egyptian priests and enriched mankind with new knowledge. The Arabs added the prefix al to the word Hemi, and the leadership in the study of substances, which became known as alchemy, passed to the Arabs. It should be noted that alchemy was not widespread in Russia, although the works of alchemists were known, and even translated into Church Slavonic. Alchemy is a medieval art of obtaining and processing various substances for practical needs. Unlike the ancient Greek philosophers, who only observed the world, and the explanation was based on assumptions and reflections, alchemists acted, experimented, making unexpected discoveries and improving the experimental methodology. Alchemists believed that metals are substances consisting of three main elements: salt - as a symbol of hardness and the ability to dissolve; sulfur - as a substance that can heat up and burn at high temperatures; mercury - as a substance capable of evaporation and possessing brilliance. In this regard, it was assumed that, for example, gold, which was a precious metal, also has exactly the same elements, which means that it can be obtained from any metal! It was believed that obtaining gold from any other metal is associated with the action of the philosopher's stone, which alchemists unsuccessfully tried to find. In addition, they believed that if you drink an elixir made from the philosopher's stone, you will gain eternal youth! But the alchemists failed to find and obtain neither the philosopher's stone nor gold from other metals.

The role of chemistry in human life.

Students list all aspects of the positive impact of chemistry on human life. The teacher helps and guides the thoughts of the students.

Teacher: But is chemistry only useful in society? What problems arise in connection with the use of chemical products?

(Students are trying to find the answer to this question as well.)

Methods of knowledge in chemistry.

A person receives knowledge about nature with the help of such an important method as observation.

Observation- this is the concentration of attention on cognizable objects in order to study them.

With the help of observation, a person accumulates information about the world around him, which he then systematizes, revealing general patterns of observation results. The next important step is to search for reasons that explain the patterns found.

In order for the observation to be fruitful, a number of conditions must be met:

clearly define the subject of observation, i.e., what the observer’s attention will be drawn to - a specific substance, its properties or the transformation of some substances into others, the conditions for the implementation of these transformations, etc.;

to formulate the purpose of the observation, the observer must know why he conducts the observation;

develop an observation plan to achieve the goal. To do this, it is better to put forward an assumption, that is, a hypothesis (from the Greek. Hypothesis - foundation, assumption) about how the observed phenomenon will occur. A hypothesis can also be put forward as a result of observation, that is, when a result is obtained that needs to be explained.

Scientific observation is different from observation in the everyday sense of the word. As a rule, scientific observation is carried out under strictly controlled conditions, and these conditions can be changed at the request of the observer. Most often, such observation is carried out in a special room - a laboratory.

Experiment- scientific reproduction of a phenomenon for the purpose of its study, testing under certain conditions.

Experiment (from lat. experimentum - experience, test) allows you to confirm or refute the hypothesis that arose during the observation, and formulate a conclusion.

Let's conduct a small experiment to study the structure of the flame.

Light a candle and carefully examine the flame. It is heterogeneous in color, has three zones. The dark zone (1) is at the bottom of the flame. She is the coldest among the others. The dark zone is bordered by the bright part of the flame (2), the temperature of which is higher than in the dark zone. However, the highest temperature is in the upper colorless part of the flame (zone 3).

To make sure that different zones of the flame have different temperatures, you can conduct such an experiment. Let's place a splinter or match in the flame so that it crosses all three zones. You will see that the splinter is charred in zones 2 and 3. This means that the temperature of the flame is the highest there.

The question arises whether the flame of an alcohol lamp or dry fuel will have the same structure as the flame of a candle? The answer to this question can be two assumptions - hypotheses: 1) the structure of the flame will be the same as the flame of a candle, because it is based on the same process - combustion; 2) the structure of the flame will be different, since it arises as a result of the combustion of various substances. In order to confirm or refute one of these hypotheses, let us turn to the experiment - we will conduct an experiment.

We investigate with the help of a match or a splinter the structure of the flame of an alcohol lamp.

Despite the differences in shape, size and even color, in both cases the flame has the same structure - the same three zones: the inner dark (coldest), the middle luminous (hot) and the outer colorless (hottest).

Therefore, on the basis of the experiment, we can conclude that the structure of any flame is the same. The practical significance of this conclusion is as follows: in order to heat any object in a flame, it must be brought into the upper, i.e., the hottest, part of the flame.

It is customary to draw up experimental data in a special laboratory journal, for which an ordinary notebook is suitable, but strictly defined entries are made in it. They note the date of the experiment, its name, the course of the experiment, which is often drawn up in the form of a table.

Try to describe an experiment on the structure of a flame in this way.

All natural sciences are experimental. And to set up an experiment, special equipment is often required. For example, in biology, optical instruments are widely used, which allow you to magnify the image of the observed object many times over: a magnifying glass, a microscope.

Physicists in the study of electrical circuits use instruments to measure voltage, current, and electrical resistance.

Scientists-geographers are armed with special instruments - from the simplest (compass, meteorological probes) to research ships, unique space orbital stations.

Chemists also use special equipment in their research. The simplest of them is, for example, a heating device already familiar to you - an alcohol lamp and various chemical utensils in which transformations of substances are carried out, that is, chemical reactions.

IV Generalization and systematization of acquired knowledge.

So what does chemistry study? (During the lesson, the teacher paid attention to the correctness or incorrectness of the children's assumptions about the subject of chemistry. And now the time has come to summarize and give the final answer. We derive the definition of chemistry).

What role does chemistry play in human life and society?

What methods of knowledge in chemistry do you now know.

What is observation? What conditions must be met in order for the observation to be effective?

What is the difference between a hypothesis and a conclusion?

What is an experiment?

What is the structure of a flame?

How should the heating be done?

V Reflection, summing up the lesson, grading.

VI Communication of homework, briefing on its implementation.

Teacher: You must:

Learn the base notes for this lesson.

Describe the experiment to study the structure of the flame using the table below.