Diamond is simple or complex. Sophisticated substances. Types of structure of substances

About atoms and chemical elements

There is no other nature in nature

neither here, nor there, in cosmic depths:

all - from the sands of small to the planets -

from elements consists of uniform.

S. P. Shipachev, "Reading Mendeleev".

In chemistry except terms "atom" and "molecule" Often used concept "element". What is common and how do these concepts vary?

Chemical element – these are atoms of the same type. . For example, all hydrogen atoms are an element of hydrogen; All oxygen and mercury atoms are, respectively, elements of oxygen and mercury.

Currently, more than 107 species of atoms are known, that is, more than 107 chemical elements. It is necessary to distinguish the concepts of "chemical element", "atom" and "simple substance"

Simple I. sophisticated substances

On elemental composition distinguish simple substancesconsisting of atoms of one element (H 2, O 2, CL 2, P 4, NA, CU, AU), and sophisticated substancesconsisting of atoms of different elements (H 2 O, NH 3, of 2, H 2 SO 4, MgCl 2, K 2 SO 4).

Currently, 115 chemical elements are known that form about 500 substances.

Nerogenic gold is a simple substance.

The ability of one element to exist in the form of various simple substancesdiffering in properties called allhotropia. For example, the element oxygen O has two allotropic forms - dicksorod O 2 and ozone O 3 with different numbers of atoms in molecules.

Allotropic forms of carbon element C - diamond and graphite - the structure of their crystals differs. There are other causes of allotropy.

chemical compounds, for example, the oxide of mercury (II) HGO (obtained by connecting atoms of simple substances - mercury Hg and oxygen O 2), sodium bromide (obtained by connecting atoms of simple substances - sodium Na and Bromine BR 2).

So, summarize the foregoing. Molecules of matter have two types:

1. Simple- Molecules of such substances consist of atoms of one species. In chemical reactions, it cannot be discharged with the formation of several more simple substances.

2. Sophisticated- molecules of such substances consist of atoms of different types. In chemical reactions can be detected with the formation of simpler substances.

Distinction of concepts " chemical element"And" simple substance "

Distribute concept "chemical element" and "Simple substance" It is possible when comparing the properties of ordinary and complex substances. For example, a simple substance - oxygen- Colorless gas required for breathing, supporting burning. The smallest particle of a simple oxygen substance is a molecule that consists of two atoms. Oxygen is also included in the total carbon oxide (carbon monoxide) and water. However, the composition of water and carbon oxide includes chemically bound oxygen, which does not have the properties of a simple substance, in particular it cannot be used for breathing. Fish, for example, breathe not by chemically bound oxygen, which is part of the water molecule, and free, dissolved in it. Therefore, when it comes to the composition of any chemical compounds, it should be understood that these compounds include not simple substances, but atoms of a certain species, that is, the corresponding elements.

In case of decomposition of complex substances, atoms can be released in free state and connecting, forming simple substances. Simple substances consist of one element atoms. The difference in the concepts "chemical element" and "simple substance" is confirmed by the fact that the same element can form several simple substances. For example, the atoms of the oxygen element may form dioxide oxygen molecules and trekatomic - ozone. Oxygen and ozone are completely different simple substances. This explains the fact that simple substances are known much more than chemical elements.

Using the concept of "chemical element", it is possible to give such a definition by simple and complex substances:

Simples call such substances that consist of atoms of one chemical element.

Complicated are such substances that consist of atoms of different chemical elements.

The difference between the concepts of "mixture" and "chemical compound"

Complex substances are often called Chemical compounds.

Try answering questions:

1. Why differ in the composition of the mixture from chemical compounds?

2. Match the properties of mixtures and chemical compounds?

3. What methods can be divided into components of the mixture and chemical compound?

4. Is it possible to judge the external signs of the formation of a mixture and chemical compound?

Comparative characteristics of mixtures and chemical

Questions for comparing mixtures with chemical compounds	Comparison
	Mixes	Chemical compounds
What differ in the composition of the mixture from chemical compounds?	Substances can be mixed in any relations, i.e. Composition of mixes variable	The composition of chemical compounds is permanent.
Match the properties of mixtures and chemical compounds?	Substances in mixtures save their properties	Substances that form connections are not preserved their properties, as chemical compounds with other properties are formed
What methods can be divided into components of the mixture and chemical compound?	Substances can be divided by physical ways	Chemical compounds can be decomposed only with the help of chemical reactions.
Is it possible to judge the external signs of the formation of a mixture and chemical compound?	Mechanical mixing is not accompanied by heat release or other signs of chemical reactions.	The formation of a chemical compound can be judged by the signs of chemical reactions.

Tasks for fixing

I. Work with simulators

II. Decide the task

From the proposed list of substances, write separately simple and complex substances:
NaCl, H 2 SO 4, K, S 8, CO 2, O 3, H 3 PO 4, N 2, FE.
Explain your choice, in each case.

III. Answer the questions

№1

How many simple substances are recorded in a number of formulas:
H 2 O, N 2, O 3, HNO 3, P 2 O 5, S, FE, CO 2, KOH.

№2

Both substances include complex:

A) C (coal) and s (sulfur);
B) CO 2 (carbon dioxide) and H 2 O (water);
C) Fe (iron) and CH 4 (methane);
D) H 2 SO 4 ( sulfuric acid) and H 2 (hydrogen).

№3

Choose Proper Approval:
Simple substances consist of one type atoms.

A) Vero

B) incorrect

№4

For mixtures, it is characteristic that
A) they have a permanent composition;
B) substances in the composition of the "mixture" do not retain their individual properties;
C) substances in "mixtures" can be divided by physical properties;
D) substances in "mixtures" can be divided by a chemical reaction.

№5

For "chemical compounds", the following is characteristic:
A) variable composition;
B) substances, in the composition of the "chemical compound" can be divided by physical ways;
C) the formation of a chemical compound can be judged on the signs of chemical reactions;
D) constant composition.

№6

In which case we are talking about iron like O. chemical element?
A) iron is a metal that is attracted by a magnet;
B) iron is included with the composition of rust;
C) for iron is characterized by metallic shine;
D) One atom of iron is included in the iron sulfide.

№7

In which case we are talking about oxygen as a simple substance?
A) oxygen is gas, supports breathing and burning;
B) the fish breathe oxygen dissolved in water;
C) an oxygen atom is part of the water molecule;
D) Oxygen is part of the air.

The main difference between them - in their composition. Thus, simple substances include one element atoms. Their (simple substances) crystals can be synthesized in laboratory, and sometimes at home. However, it is often necessary to create certain conditions for the storage of the obtained crystals.

There are five classes on which simple substances are divided: metals, semimetals, non-metals, intermetallides and halogens (not found in nature). They can be represented by atomic (AR, not) or molecular (O2, H2, O3) gases.

As an example, you can take a simple substance oxygen. It includes molecules consisting of two oxygen element atoms. Or, for example, iron substance consists of crystals, including only iron element atoms. Historically, it is not possible to call a simple substance by the name of the element, the atoms of which are included in its composition. The structure of these compounds may be molecular and nelecular.

Complex substances include atoms of various types And when decomposition can form two (or more) compounds. For example, water at splitting forms oxygen and hydrogen. In this case, not each compound can be decomposed on simple substances. For example, iron sulphide formed by sulfur and iron atoms is not cleavage. In this case, in order to prove that the compound is complex and includes heterogeneous atoms, apply the principle of reverse reaction. In other words, with the help of the source components, iron sulfide is obtained.

Simple substances are forms of chemical elements that exist in free form. Today, more than four hundred species of these elements are known science.

Unlike complicated substances, simple cannot be obtained from other simple substances. They are also impossible to decompose on other connections.

Everything allotropic modifications Possess the property to move in each other. Different types of simple substances formed by one chemical element may have different and different levels of chemical activity. For example, oxygen exhibits smaller than ozone, activity, and the melting point of fullerene, for example, less than that of the diamond.

Under normal conditions for eleven elements, simple substances will be gases (AR, XE, RN, N, H, NE, O, F, KR, CL, HE,), for two liquids (Br, Hg), and for other elements - solid bodies.

At temperatures close to room, five metals will take a liquid or semi-liquid state. This is due to the fact that the temperature of their melting is almost so, mercury and rubidium are melted at 39 degrees, France - at 27, cesium - at 28, and gallium at 30 degrees.

It should be noted that the concepts of "chemical element", "atom", "simple substance" mix should not be mixed. For example, an atom has a certain, concrete value and is real. The definition of the "chemical element" is generally abstract collective. In nature, elements are present in the form of atoms free or chemically related. At the same time, the characteristics of simple substances (the totality of particles) and the chemical elements (isolated atoms of a particular species) have their own characteristics.

Simple and complex substances. Chemical element

About atoms and chemical elements

In chemistry, in addition to the terms "atom" and "molecule", the concept of "element" is often used. What is common and what these concepts differ?

Chemical element - These are the atoms of the same species. For example, all hydrogen atoms are an element of hydrogen; All oxygen and mercury atoms are, respectively, elements of oxygen and mercury.

Currently, more than 107 species of atoms are known, that is, more than 107 chemical elements. It is necessary to distinguish the concepts of "chemical element", "atom" and "simple substance"

Simple and complex substances

Elemental composition differences simple substances consisting of atoms of one element (H2, O2, CL2, P4, Na, Cu, AU), and complex substances consisting of atoms of different elements (H2O, NH3, OF2, H2SO4, MgCl2, K2SO4) .

Currently, 115 chemical elements are known that form about 500 simple substances.

Nerogenic gold is a simple substance.

The ability of one element to exist in the form of various simple substances, differing in properties, is called allotropy. For example, an oxygen element O has two allotropic forms - O2 dicksorod and ozone O3C with different number of atoms in molecules.

Allotropic forms of carbon element C - diamond and graphite - the structure of their crystals differs. There are other causes of allotropy.

Allotropic carbon forms:

graphite:

diamond:

The complex substances are often referred to as chemical compounds, such as the oxide of mercury (II) HGO (obtained by connecting the atoms of simple substances - mercury Hg and oxygen O2), sodium bromide (obtained by connecting atoms of simple substances - sodium Na and bromine BR2).

So, summarize the foregoing. Molecules of matter have two types:

1. Simple - Molecules of such substances consist of atoms of one species. IN chemical reactions Cannot decompose with the formation of several simpler substances.

2. Sophisticated- Molecules of such substances consist of atoms of different types. In chemical reactions can be detected with the formation of simpler substances.

The difference in the concepts of "chemical element" and "simple substance"

Distinguish the concept of "chemical element" and "simple substance" when comparing the properties of simple and complex substances. For example, a simple substance is oxygen - a colorless gas required for breathing that supports burning. The smallest particle of a simple oxygen substance is a molecule that consists of two atoms. Oxygen is also included in the total carbon oxide (carbon monoxide) and water. However, the composition of water and carbon oxide includes chemically bound oxygen, which does not have the properties of a simple substance, in particular it cannot be used for breathing. Fish, for example, breathe not by chemically bound oxygen, which is part of the water molecule, and free, dissolved in it. Therefore, when it comes to the composition of any chemical compounds, it should be understood that these compounds include not simple substances, but atoms of a certain species, that is, the corresponding elements.

In case of decomposition of complex substances, atoms can be released in free state and connecting, forming simple substances. Simple substances consist of one element atoms. The difference in the concepts "chemical element" and "simple substance" is confirmed by the fact that the same element can form several simple substances. For example, the atoms of the oxygen element may form dioxide oxygen molecules and trekatomic - ozone. Oxygen and ozone are completely different simple substances. This explains the fact that simple substances are known much more than chemical elements.

Using the concept of "chemical element", it is possible to give such a definition by simple and complex substances:

Simple Call such substances that consist of atoms of one chemical element.

Complicated Called such substances that consist of atoms of different chemical elements.

The difference between the concepts "mixture" and " chemical compound»

Sophisticated substances are often called chemical compounds.

Follow the link and review the experience of the interaction of simple substances of iron and sulfur.

Try answering questions:

1. Why differ in the composition of the mixture from chemical compounds?

2. Match the properties of mixtures and chemical compounds?

3. What methods can be divided into components of the mixture and chemical compound?

4. Is it possible to judge the external signs of the formation of a mixture and chemical connection?

Comparative characteristics of mixtures and chemical connections

Questions for comparing mixtures with chemical compounds	Comparison
	Mixes	Chemical compounds
What differ in the composition of the mixture from chemical compounds?	Substances can be mixed in any relations, i.e. Composition of mixes variable	The composition of chemical compounds is permanent.
Match the properties of mixtures and chemical compounds?	Substances in mixtures save their properties	Substances that form connections are not preserved their properties, as chemical compounds with other properties are formed
What methods can be divided into components of the mixture and chemical compound?	Substances can be divided by physical ways	Chemical compounds can be decomposed only with the help of chemical reactions.
Is it possible to judge the external signs of the formation of a mixture and chemical compound?	Mechanical mixing is not accompanied by heat release or other signs of chemical reactions.	The formation of a chemical compound can be judged by the signs of chemical reactions.

Tasks for fixing

I. Work with simulators

Simulator №1

Simulator №2.

Simulator number 3.

II. Decide the task

From the proposed list of substances, write separately simple and complex substances:

NaCl, H2SO4, K, S8, CO2, O3, H3PO4, N2, FE.

Explain your choice, in each case.

III. Answer the questions

№1

How many simple substances are recorded in a number of formulas:

H2O, N2, O3, HNO3, P2O5, S, FE, CO2, KOH.

№2

Both substances include complex:

A) C (coal) and s (sulfur);

B) CO2 (carbon dioxide) and H2O (water);

C) FE (iron) and CH4 (methane);

D) H2SO4 (sulfuric acid) and H2 (hydrogen).

№3

Choose Proper Approval:

Simple substances consist of one type atoms.

A) Vero

B) incorrect

№4

For mixtures, it is characteristic that

A) they have a permanent composition;

B) substances in the composition of the "mixture" do not retain their individual properties;

C) substances in "mixtures" can be divided by physical properties;

D) substances in "mixtures" can be divided by a chemical reaction.

№5

For "chemical compounds", the following is characteristic:

A) variable composition;

B) substances, in the composition of the "chemical compound" can be divided by physical ways;

C) the formation of a chemical compound can be judged on the signs of chemical reactions;

D) constant composition.

№6

In which case we are talking about the gland as a chemical element?

A) iron is a metal that is attracted by a magnet;

B) iron is included with the composition of rust;

C) for iron is characterized by metallic shine;

D) One atom of iron is included in the iron sulfide.

№7

In which case we are talking about oxygen as a simple substance?

A) oxygen is gas, supports breathing and burning;

B) the fish breathe oxygen dissolved in water;

C) an oxygen atom is part of the water molecule;

D) Oxygen is part of the air.

§ 9. Simple and complex substances

Having mastered this topic, you can:

Discern the concepts of "simple substance" and "complex substance", formulas of simple and complex substances;

Understand the concept of "chemical compound";

Give examples of simple and complex substances;

Describe simple and complex substances known for you from everyday use;

Express judgments about the variety of substances.

Most chemical element atoms have the ability to combine each other or with atoms of other chemical elements. As a result, chemical compounds are formed. Regardless of the composition of their structural particles and simple, and complex substances are chemical compounds, since chemical bonds arise between them.

You have already familiarized yourself with the structure of atoms of chemical elements. Substances that make up atoms are called atomic.

However, among the entire variety of chemical compounds there are molecular substances. The component of them are molecules.

Molecules are the smallest particles of substances that retain its chemical properties.

The molecule is considered the limness of the substance. If it is destroyed, the substance is also destroyed. A characteristic feature of molecules is a continuous movement.

Recall the course of natural science, which phenomenon is called diffusion.

Each molecule consists of a certain amount of atoms of one or various chemical elements.

Recompons from the course of natural science, how to share substances in composition and origin.

What substances call: a) simple; b) complex? Give some examples of simple and complex substances that you most often use in everyday life.

Simple substances are substances formed by one chemical element.

For example, simple substances are hydrogen, oxygen, nitrogen formed in accordance with the chemical elements of the gіrogen, oxygen, nitrogen. The composition of their molecules includes two interconnected atoms of these elements (Fig. 41 A, 6, B).

Element oxygen certain conditions It forms another simple substance - ozone, the molecule of which contains three atoms (Fig. 41 g).

Fig. 41. Models of molecules of simple substances: a - hydrogen; b - oxygen; in - ozone; G - Nitrogen

Painst substances are substances formed by two or more chemical elements.

Substances relate to complex substances; water, sugar, soap, salt, chalk, methane (natural gas component), carbon dioxide. Substances included in the cells of living organisms (proteins, fats and carbohydrates) are complex and mainly mainly carbon atoms, oxygen, hydrogen, nitrogen, sulfur, phosphorus and have a molecular structure.

Remember how to prove that water is a complex substance. What research methods used scientists to determine the composition of the water?

Figure 42 shows models of methane molecules, carbon dioxide and water. Molecule consists of one carbon atom and four hydrogen atoms, carbon dioxide molecule - from one carbon atom and two oxygen atoms, water molecule - from one oxygen atom and two hydrogen atoms.

Fig. 42. Models of molecules of complex substances: A - methane; b - carbon dioxide; in water

So, depending on the composition, the substances are classified into simple and complex. The classification scheme of substances is shown in Figure 43.

Fig. 43. Classification of substances

Simple substances: metals and non-metals. Simple substances are separated by two groups. Metal elements form metals, nonmetallic - non-metals. They are distinguished by physical properties.

Remember, with what physical properties of substances you have already familiarized. Name them.

We turn to the demonstrations and consider the samples of simple substances of metals and non-metals. From metals the most common in the technique, various industries, everyday life with iron, zinc, aluminum, copper, silver, gold; From non-metals in the laboratory there are sulfur, carbon, red phosphorus, bromine, iodine.

Pay attention to the aggregate state of metals and non-metals. Why do you think the bromine is stored in sealed ampoules?

As a basis for dividing simple substances PA metals and nonmetals taken them physical properties (Table 2).

table 2

Physical properties of simple substances

Nonmetals are substances that are mostly consisting of molecules. Molecules of many of them are diatomic. However, multiatomic molecules are found: already mentioned ozone, crystalline sulfur - contains eight sulfur atoms, white phosphorus - four atoms of this element. In simple substances formed by element carbon, atoms are connected in a certain order without forming molecules.

Metals consist of atoms of the corresponding elements. Metal names often coincide with the names of metal elements that form them. For example, aluminum substances, zinc, nickel, chromium, magnesium formed by the corresponding chemical elements. However, the substance copper consists of an element atoms of thember, silver - argentum, gold - aurum, mercury - mercury, iron. The names of non-metals of elements and simple substances coincide for a slight amount of substances (Table 3).

Table S.

Names of chemical elements and simple substances

Metal		Non-metallic
Chemical element	Simple substance	Chemical element	Simple substance
Aluminum	aluminum
Argentum
Mercury			oxygen

Laboratory experience 2.

Acquaintance with samples of simple and complex substances

Task 1. Consider attentively substances issued to you in banks. Read label inscriptions: H 2 O (water), S (sulfur), P (phosphorus), Mg (magnesium), NaOH (sodium hydroxide), C (carbon), Fe 3 O 4 (Ferum (II, III) oxide ), Fe (iron), zno (zinc oxide), Saco 3 (calcium carbonate), AL (aluminum), Zn (zinc), CAO (calcium oxide), NA 2 CO 3 (sodium carbonate).

Distribute these substances into two groups: simple and complex. Simple classifies substances to metals and non-metals.

Task 2. Describe: a) what is the difference in the composition of simple and complex substances; 6) For what features you made a classification.

Task 3. Describe the physical properties of substances based on your observations.

By clicking, write down the data into the workbook in the form of a table. At the end of the work, formulate conclusions.

substances		substances	Description of observation properties
Nemetalla

Mature of substances. The diversity of substances is explained by the ability of the element atoms to be combined with each other. Depending on which atoms, in what quantity are also connected, many simple and complex substances are formed (Fig. 44).

Fig. 44. A simple substance of the sulfur (A) and a complex substance Amethyst (b)

Simple substances exist a little more than chemical elements - 400, for, as you already know, the same element (hydroxygen, carbon, phosphorus, sulfur) can form two or more substances.

Painst substances are known much more (almost 20 mills). This is water, the composition of the molecule of which includes hydrogen and oxygen, carbon dioxide - carbon and oxygen, sodium sodium and chlorine. The composition of these substances includes only two elements - this binary compounds. However, a significant amount of substances consists of three or more elements. Thus, the glucose includes three elements: carbon, hydrogen and hydroxygen, and drinking sodes contains four elements: sodium, hydrogen, carbon and oxygen.

It includes everything organic substances. In addition, there is a whole industry in the extraction of synthetic and artificial compounds that have a huge manufacturing and domestic purpose.

Recall the course of natural science, which substances are called inorganic, organic. Give examples of inorganic and organic compounds.

Under normal conditions (temperature 0 ° C, pressure 101.3 kPa) substances are in three aggregate states: liquid (water, oil, alcohol), solid (zinc, iron, sulfur, phosphorus, carbon, copper) and gazowent (hydrogen, oxygen, ozone, nitrogen, carbon dioxide, inert gases).

We summarize the studied

Substances are divided into simple and complex.

Sophisticated substances are formed from two or more chemical elements. They are much larger than simple.

Each simple and complex substance is characterized by certain properties, that is, the signs for which their similarity and difference can be identified.

Sophisticated substances are organic and inorganic origin.

The diversity of substances is explained by the ability of the element atoms to be combined with each other.

Tasks for knowledge control

1. Explain that they mean the concepts of "molecule", "simple substance", "complex substance", "chemical compound".

2. Give examples: a) simple and complex substances; b) organic and inorganic substances.

3. Justify whether the concepts "chemical compound" and the "mixture of substances" are identical.

4. Describe physical properties: a) sugar; b) water; c) oil.

5. Justify why complex substances are larger than simple.

6. Specify your own judgment about the importance of substances for the life and human health.

INTERESTING TO KNOW

The English Chemist of Davy first allocated in a free state, the electrolysis method, sodium metals, potassium, calcium, strontium, barium, magnesium. These works laid the beginning of the manufacture of strong lamps for spotlights, lighthouses, etc. Subsequently, the scientist created a secure mining lamp, which was used all over the world until he was replaced with a battery light bulb.

Sklodovskaya-Curie Maria (1867-1934) - French physicist and chemist, teacher, public figure. Science is obliged to the discovery and study of two radioactive elements - polonium and radium. Opening of the element of the radium began the method for the treatment of skin cancer. For his work was awarded by two Nobel Prizes, who sacrificed to the construction of a sanatorium in Zakopane and the Radiological Institute in the city of Warsaw (Poland).

All substances we are talking about school course Chemistry, it is customary to divide on simple and complex. Simple substances are such substances, the molecules of which include atoms of the same element. Atomic oxygen (O), molecular oxygen (O2) or just oxygen, ozone (O3), graphite, diamond are examples of simple substances that form chemical elements oxygen and carbon. Sophisticated substances are divided into organic and inorganic. Among the inorganic substances, first of all identify the following four classes: oxides (or oxides), acids (acid and oxygen), base (soluble bases are called alkalis) and salts. The unmetalov compounds (excluding oxygen and hydrogen) are not included in these four classes, we will call them conditionally "and other complex substances."

Simple substances are made to divide on metals, non-metals and inert gases. Metals include all chemical elements that are filling D- and F-sublevels, it is in the 4th period of the elements: SC - Zn, in the 5th period: y - CD, in the 6th period: La - Hg, CE - LU, in the 7th AC - Th - LR period. If now among the remaining elements, to spend the line from BE to AT, then the metal will be located on the left and at the bottom of it, and the on the right and at the top are non-metals. In 8 group Periodic system There are inert gases. Elements located on the diagonal: AL, GE, SB, PO (and some others. For example, Zn) in the free state have the properties of metals, and hydroxides have properties and bases, and acids, i.e. are amphoteric hydroxides. Therefore, these elements can be considered metal-non-metals that occupy an intermediate position between metals and non-metals. Thus, the classification of chemical elements depends on what properties their hydroxides will possess: the main means it means metal, nonmetall, and those and others (depending on the conditions) - nonmetall. The same chemical element in compounds with a lower positive degree of oxidation (Mn + 2, Cr + 2) exhibits pronounced "metal" properties, and in compounds with a maximum positive degree of oxidation (Mn + 7, Cr + 6) exhibits the properties of a typical Nemetalla. To see the relationship of simple substances, oxides, hydroxides and salts, we give a consolidated table.