All chemical elements can be characterized depending on the structure of their atoms, as well as by their position in the Periodic system of D.I. Mendeleev. Usually, the characteristics of a chemical element are given according to the following plan:

• indicate the symbol of the chemical element, as well as its name;
• based on the position of the element in the Periodic system of D.I. Mendeleev indicate its ordinal, period number and group (type of subgroup) in which the element is located;
• based on the structure of the atom, indicate the nuclear charge, mass number, the number of electrons, protons and neutrons in the atom;
• write down the electronic configuration and indicate the valence electrons;
• draw electron-graphic formulas for valence electrons in the ground and excited (if possible) states;
• indicate the family of the element, as well as its type (metal or non-metal);
• indicate the formulas of higher oxides and hydroxides with a brief description of their properties;
• indicate the values ​​of the minimum and maximum oxidation states of a chemical element.

Characteristics of a chemical element using the example of vanadium (V)

Consider the characteristics of a chemical element using the example of vanadium (V) according to the plan described above:

1. V - vanadium.

2. Ordinal number - 23. The element is in the 4th period, in the V group, A (main) subgroup.

3. Z=23 (nuclear charge), M=51 (mass number), e=23 (number of electrons), p=23 (number of protons), n=51-23=28 (number of neutrons).

4. 23 V 1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 2 – electronic configuration, valence electrons 3d 3 4s 2 .

5. Basic state

excited state

6. d-element, metal.

7. The highest oxide - V 2 O 5 - exhibits amphoteric properties, with a predominance of acidic:

V 2 O 5 + 2NaOH \u003d 2NaVO 3 + H 2 O

V 2 O 5 + H 2 SO 4 \u003d (VO 2) 2 SO 4 + H 2 O (pH<3)

Vanadium forms hydroxides of the following composition V(OH) 2 , V(OH) 3 , VO(OH) 2 . V(OH) 2 and V(OH) 3 are characterized by basic properties (1, 2), and VO(OH) 2 has amphoteric properties (3, 4):

V (OH) 2 + H 2 SO 4 \u003d VSO 4 + 2H 2 O (1)

2 V (OH) 3 + 3 H 2 SO 4 \u003d V 2 (SO 4) 3 + 6 H 2 O (2)

VO(OH) 2 + H 2 SO 4 = VOSO 4 + 2 H 2 O (3)

4 VO (OH) 2 + 2KOH \u003d K 2 + 5 H 2 O (4)

8. Minimum oxidation state "+2", maximum - "+5"

Examples of problem solving

EXAMPLE 1

Exercise

Describe the chemical element phosphorus

Decision

1. P - phosphorus. 2. Ordinal number - 15. The element is in the 3rd period, in the V group, A (main) subgroup. 3. Z=15 (nuclear charge), M=31 (mass number), e=15 (number of electrons), p=15 (number of protons), n=31-15=16 (number of neutrons). 4. 15 P 1s 2 2s 2 2p 6 3s 2 3p 3 – electronic configuration, valence electrons 3s 2 3p 3 . 5. Basic state excited state 6. p-element, non-metal. 7. The highest oxide - P 2 O 5 - exhibits acidic properties: P 2 O 5 + 3Na 2 O \u003d 2Na 3 PO 4 The hydroxide corresponding to the higher oxide - H 3 PO 4, exhibits acidic properties: H 3 PO 4 + 3NaOH \u003d Na 3 PO 4 + 3H 2 O 8. The minimum oxidation state is "-3", the maximum is "+5"

EXAMPLE 2

Exercise	Describe the chemical element potassium
Decision	1. K - potassium. 2. Ordinal number - 19. The element is in period 4, in group I, A (main) subgroup.

Lesson topic: Characteristics of a chemical element based on its position in the Periodic Table of D.I. Mendeleev

The purpose of the lesson: To expand and deepen the knowledge gained in the construction of atoms of chemical elements from the 8th grade chemistry course.

To teach how to draw up a plan for the characteristics of a chemical element, based on its position in the Periodic system and the structure of the atom.

During the classes:

1. Organizational moment.

2. Repetition of the PSCE structure.

Patterns of changes in the properties of chemical elements and their compounds by periods and groups

The chemical properties of elements (and even more so their compounds!) directly depend on

Reminder!!! No need to memorize the chemical properties of each atom, no need to memorize chemical reactions ... the answer to any question in chemistry is in .

3. Learning new material.

Chemical elements in the Periodic system are heroes, and they, like any heroes, need to be given certain characteristics. As a basis for their characteristics, one must take the Periodic Table of Chemical Elements of D.I. Mendeleev. It will be necessary to describe the chemical element according to 7 points: firstly, it is necessary to indicate the position of the element in the Periodic system of D.I. Mendeleev and the structure of his atom, then the nature of a simple substance, i.e. this chemical element is a metal or non-metal, compare the properties of a simple substance with the properties of simple substances formed by elements adjacent in a subgroup, and also compare the properties of a simple substance with the properties of simple substances formed by elements adjacent in a period, only after that determine the composition of the higher oxide and its nature (basic, acidic, amphoteric), and on the basis of the oxide and the composition of the higher hydroxide, its character (oxygen-containing acid, base, amphoteric hydroxide), and for non-metals, also indicate the composition of the volatile hydrogen compound.

For atoms of chemical elements in groups, the charge of the nucleus of atoms increases from top to bottom, which is numerically equal to the ordinal number of the element, the radius of atoms also increases, because the number of energy levels increases, and the number of energy levels is determined by the number of the period, while the number of electrons remains unchanged, the electrons move farther and farther away from the nucleus, so it becomes easier to give them away and the reducing properties are enhanced, and the oxidizing properties are weakened. At the same time, the highest oxidation state remains unchanged and is equal to the group number, the lowest oxidation state also does not change and is equal to group number - 8. In periods from left to right, the charge of the nucleus also increases, and the radius, on the contrary, decreases, because the number of electrons at the outer level increases, which is determined by the group number, and the electrons are more tightly bound to the nucleus, while the number of energy levels remains unchanged. Therefore, the reducing properties weaken, and the oxidizing ones increase. The highest oxidation state varies from +1 to +8: in the first group - +1, in the second - +2, in the third - +3, in the fourth - +4, in the fifth - +5, and the lowest from -4 to - : in the fourth group it is -4, in the fifth -3, in the sixth -2, and in the seventh -1.

With regard to simple substances, the metallic properties in groups increase from top to bottom, and weaken in periods from left to right. Non-metallic properties, on the contrary, weaken from top to bottom in groups, and increase in periods from left to right.

For compounds of chemical elements, it is characteristic that in groups, from top to bottom, the basic properties increase, while the acid ones weaken. For example, in the first group, the main properties of potassium oxide are more pronounced than those of lithium oxide, and in the fourth group, silicon oxide ( IV ) acidic properties are more pronounced than those of lead oxide ( IV ). In periods, from left to right, acidic properties increase, and basic ones weaken. For example, in magnesium oxide, the main properties are more pronounced than in aluminum oxide, in carbon monoxide ( IV ) acidic properties are more pronounced than those of boron oxide.

Let us characterize sodium metal in all respects. Serial number of sodium, i.e. the cell in which he stands is 11. The mass number is 23. Hence, the charge of his nucleus is +11, Z \u003d +11 (the charge of the nucleus of an atom is equal to the serial number of the element, the number of protons and the number of electrons). Therefore, there are 11 electrons in an atom (11 ē), and the number of neutrons is determined by the formula N = A – Z , i.e. 23 - 11 \u003d 12, which means there are 12 neutrons in the atom (12 n ).

Sodium is in the 3rd period, which means that it will have 3 energy levels, on which all its electrons will be located. There are 2 electrons on the first level (this is the maximum), on the second - 8, on the third, which means - 1 electron.

Because sodium has 1 electron in the outer level, then this element belongs to metals. In reactions, it will donate 1 electron, exhibiting reducing properties, and receive an oxidation state of +1.

Now we need to characterize sodium as a simple substance. Since sodium is a metal, it is characterized by a metallic chemical bond and a metallic crystal lattice. Therefore, as for any metal, it is characterized by such physical properties as metallic luster, ductility, heat and electrical conductivity.

Now we need to compare the properties of sodium with the properties of its neighbors in the group: the metallic properties of sodium are more pronounced than those of lithium, but weaker than those of potassium, because. in the group from top to bottom, the radius of the atom increases and the electrons move further away from the nucleus and it becomes easier to tear them off.

And now you need to compare the properties of sodium with the properties of its neighbors in the period: the metallic properties of sodium are more pronounced than those of magnesium, because. in periods, from left to right, the radius of the atoms decreases, and the number of electrons at the outer level increases, the electrons are more tightly bound to the nucleus, so it becomes harder to tear them off than to attach them.

Now you need to make a formula for sodium oxide and determine its nature. Because sodium - metal I A group, then it corresponds to sodium oxide - Na 2 O , which means that this is a basic oxide and it exhibits all the properties characteristic of these oxides: it reacts with acids and acid oxides, with water to form an alkali.

Sodium hydroxide is NaOH , it is an alkali - a water-soluble base. It will be characterized by the following properties: reactions with acids and acid oxides, reactions with salts.

If sodium is a metal, but it does not form volatile hydrogen compounds.

Describe phosphorus. Phosphorus is in cell number 15, i.e. its serial number is 15, which means that the charge of the nucleus of its atom will be +15, and the number of protons, like the number of electrons, is 15: (p = 15, ē = 15). The mass number of phosphorus is 31, so the number of neutrons will be 16, because if we subtract the number of protons from the mass number, it will be 16 (31 - 15 = 16). Phosphorus is in the third period, which means it has three energy levels, there are 2 electrons in the first level, 8 in the second, and five in the third: (2ē, 8ē, 5ē). That. Phosphorus has 5 electrons in its outer energy level.

Phosphorus is a non-metal, which means that it can be both an oxidizing agent and a reducing agent. As an oxidizing agent, it can add 3 electrons before completing the outer level, thus obtaining an oxidation state of -3 (P 0 + 3 ē → P -3 ), and as a reducing agent, it can donate 3 or 5 electrons and get an oxidation state of +3 or +5 (P 0 - 3 ē → P +3 , R 0 - 5 ē → P +5 .

Phosphorus is a non-metal. It is characterized by the phenomenon of allotropy, as well as for sulfur. Those. it can form several simple substances that differ in their properties. For example, white phosphorus has a white color and a molecular crystal lattice, the molecule has the form of a tetrahedron, and red phosphorus is a polymer, black phosphorus is a semiconductor and has a metallic luster.

Now we need to compare the properties of phosphorus and its neighbors. The non-metallic properties of phosphorus are more pronounced than those of arsenic, but weaker than those of nitrogen, because Nitrogen has a smaller radius than phosphorus. Compared with its period neighbors, the properties of phosphorus are more pronounced than those of silicon, but weaker than those of sulfur.

It remains to draw up the formula of oxide and hydroxide of phosphorus. Higher phosphorus oxide - P 2 O 5 . It is an acidic oxide that exhibits properties characteristic of these oxides: it reacts with basic oxides, bases and water to form the corresponding acid.

The highest phosphorus hydroxide is phosphoric acid, or orthophosphoric - H 3 PO 4 , it exhibits properties characteristic of all acids: it reacts with metals, bases and basic oxides, with salts.

Phosphorus is a non-metal, therefore it has a volatile hydrogen compound - PH 3 - phosphine.

4. Fixing: completing the task on page 9, ex. 4 - 6, individual work on cards.

5. Reflection and summing up:

Choose from the statements below that match your opinion and mood, and complete the sentence according to your choice. Another 45 precious minutes of my no less precious life:

a) lost irretrievably, because ...;

b) were useful, because ...

6. Homework: §1, draw up a plan for the characteristics of a chemical element with atomic number 17, ex. 2, 7, 10.

In this lesson, you will learn about the Periodic Law of Mendeleev, which describes the change in the properties of simple bodies, as well as the shape and properties of compounds of elements, depending on the magnitude of their atomic masses. Consider how a chemical element can be described by its position in the Periodic Table.

Topic: Periodic law andPeriodic system of chemical elements of D. I. Mendeleev

Lesson: Description of an element by position in the Periodic system of elements of D. I. Mendeleev

In 1869, D.I. Mendeleev, based on the data accumulated on chemical elements, formulated his periodic law. Then it sounded like this: "The properties of simple bodies, as well as the forms and properties of the compounds of elements, are in a periodic dependence on the magnitude of the atomic masses of the elements." For a very long time, the physical meaning of DIMendeleev's law was incomprehensible. Everything fell into place after the discovery of the structure of the atom in the 20th century.

Modern formulation of the periodic law:"The properties of simple substances, as well as the forms and properties of compounds of elements, are in a periodic dependence on the magnitude of the charge of the atomic nucleus."

The charge of the nucleus of an atom is equal to the number of protons in the nucleus. The number of protons is balanced by the number of electrons in the atom. Thus, the atom is electrically neutral.

The charge of the nucleus of an atom in the periodic table is the ordinal number of the element.

Period number shows the number of energy levels, on which the electrons revolve.

Group number shows the number of valence electrons. For elements of the main subgroups, the number of valence electrons is equal to the number of electrons in the outer energy level. It is the valence electrons that are responsible for the formation of the chemical bonds of an element.

Chemical elements of the 8th group - inert gases have 8 electrons on the outer electron shell. Such an electron shell is energetically favorable. All atoms tend to fill their outer electron shell with up to 8 electrons.

What characteristics of an atom change periodically in the Periodic system?

The structure of the external electronic level is repeated.

The radius of an atom changes periodically. In a group radius increases with an increase in the period number, since the number of energy levels increases. In a period from left to right the growth of the atomic nucleus will occur, but the attraction to the nucleus will be greater and therefore the radius of the atom decreases.

Each atom tends to complete the last energy level of the elements of the 1st group on the last layer 1 electron. Therefore, it is easier for them to give it away. And it is easier for the elements of the 7th group to attract 1 electron missing to the octet. In a group, the ability to donate electrons will increase from top to bottom, since the radius of the atom increases and the attraction to the nucleus is less. In a period from left to right, the ability to donate electrons decreases because the radius of the atom decreases.

The easier an element gives off electrons from the external level, the more metallic properties it has, and its oxides and hydroxides have more basic properties. This means that the metallic properties in groups increase from top to bottom, and in periods from right to left. With non-metallic properties, the opposite is true.

Rice. 1. The position of magnesium in the table

In the group, magnesium is adjacent to beryllium and calcium. Fig.1. Magnesium ranks lower than beryllium but higher than calcium in the group. Magnesium has more metallic properties than beryllium, but less than calcium. The basic properties of its oxides and hydroxides also change. In a period, sodium is to the left, and aluminum is to the right of magnesium. Sodium will exhibit more metallic properties than magnesium, and magnesium more than aluminum. Thus, any element can be compared with its neighbors by group and period.

Acid and non-metallic properties change opposite to basic and metallic properties.

Characteristics of chlorine according to its position in the periodic system of D.I. Mendeleev.

Rice. 4. Position of chlorine in the table

. The value of the serial number 17 indicates the number of protons17 and electrons17 in the atom. Fig.4. An atomic mass of 35 will help calculate the number of neutrons (35-17 = 18). Chlorine is in the third period, which means the number of energy levels in the atom is 3. It is in the 7-A group, it belongs to the p-elements. It's non-metal. Compare chlorine with its neighbors by group and by period. The non-metallic properties of chlorine are greater than those of sulfur, but less than those of argon. Chlorine ob-la-yes-is less non-metal-li-che-ski-mi properties than fluorine and more than bromine. Let's distribute the electrons over the energy levels and write the electronic formula. The general distribution of electrons will look like this. See Fig. 5

Rice. 5. Distribution of electrons of the chlorine atom over energy levels

Determine the highest and lowest oxidation state of chlorine. The highest oxidation state is +7, since it can give 7 electrons from the last electron layer. The lowest oxidation state is -1 because chlorine needs 1 electron to complete. The formula of the highest oxide is Cl 2 O 7 (acid oxide), the hydrogen compound HCl.

In the process of donating or gaining electrons, an atom acquires conditional charge. This conditional charge is called .

- Simple substances have an oxidation state equal to zero.

Elements can show maximum oxidation state and minimum. Maximum An element shows its oxidation state when gives back all its valence electrons from the outer electronic level. If the number of valence electrons is equal to the group number, then the maximum oxidation state is equal to the group number.

Rice. 2. Position of arsenic in the table

Minimum the oxidation state of an element will show when it will accept all possible electrons to complete the electron layer.

Consider, using the example of element No. 33, the values ​​of oxidation states.

This is arsenic As. It is in the fifth main subgroup. Fig. 2. It has five electrons in its last electron level. So, giving them away, it will have an oxidation state of +5. Before the completion of the electron layer, the As atom lacks 3 electrons. By attracting them, it will have an oxidation state of -3.

The position of the elements of metals and non-metals in the Periodic system of D.I. Mendeleev.

Rice. 3. The position of metals and non-metals in the table

AT side effects subgroups are all metals . If you mentally carry out diagonal from boron to astatine , then higher this diagonal in the main subgroups will be all nonmetals , a below this diagonal - all metals . Fig.3.

1. No. 1-4 (p. 125) Rudzitis G.E. Inorganic and organic chemistry. Grade 8: textbook for educational institutions: basic level / G. E. Rudzitis, F.G. Feldman. M.: Enlightenment. 2011 176 pp.: ill.

2. What characteristics of an atom change with periodicity?

3. Give a description of the chemical element oxygen according to its position in the Periodic system of D.I. Mendeleev.

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Slides captions:

Characteristics of a chemical element based on its position in the Periodic system of chemical elements D.I. Mendeleev

Discovery of the Periodic Law In 1869, D.I. Mendeleev, based on the data accumulated on the chemical elements, formulated his periodic law. Then it sounded like this: "The properties of simple bodies, as well as the forms and properties of the compounds of elements are in a periodic dependence on the magnitude of the atomic masses of the elements." For a very long time, the physical meaning of DIMendeleev's law was incomprehensible. Everything fell into place after the discovery of the structure of the atom in the 20th century.

The modern formulation of the Periodic Law "The properties of simple substances, as well as the forms and properties of compounds of elements, are in a periodic dependence on the magnitude of the charge of the atomic nucleus."

Number of protons and electrons in an atom The charge of the nucleus of an atom is equal to the number of protons in the nucleus. The number of protons is balanced by the number of electrons in the atom. Thus, the atom is electrically neutral. The charge of the nucleus of an atom in the Periodic Table is the ordinal number of the element. The period number indicates the number of energy levels in which the electrons rotate. The group number indicates the number of valence electrons. For elements of the main subgroups, the number of valence electrons is equal to the number of electrons in the outer energy level. It is the valence electrons that are responsible for the formation of the chemical bonds of an element. Chemical elements of the 8th group - inert gases have 8 electrons on the outer electron shell. Such an electron shell is energetically favorable. All atoms tend to fill their outer electron shell with up to 8 electrons.

The number of neutrons in the nucleus If the relative atomic mass of a chemical element is designated A, the charge of the nucleus is designated Z, then the number of neutrons can be calculated by the formula: n \u003d A-Z

Change in the radius of atoms of chemical elements in groups and periods How does the radius of an atom of a chemical element change from top to bottom in groups? How does the radius of an atom of a chemical element change from left to right in periods? Why is this happening? What properties of chemical elements are associated with the radius of an atom?

The outer electron shells of inert gases contain 2 (helium) or 8 (all others) electrons and are very stable. The "octet-doublet" rule All other chemical elements, entering into reactions, tend to have an outer electron shell like inert gases. The atoms of which chemical elements donate electrons most easily, and which ones take them away?

Oxidation state In the process of donating or gaining electrons, an atom acquires a conditional charge. This conditional charge is called the oxidation state. - Simple substances have an oxidation state equal to zero. - Elements can show a maximum degree of oxidation and a minimum. The element shows its maximum oxidation state when it gives up all its valence electrons from the outer electronic level. If the number of valence electrons is equal to the group number, then the maximum oxidation state is equal to the group number.

Characterization of chlorine by its position in the PSCE

Characterization plan for a chemical element 1. Element symbol a. The ordinal number of the element b. The value of the relative atomic mass of an element. in. The number of protons, electrons, neutrons. d. Period number. e. Number and type of group (element type s -, p -, d -, f - element) 2. Metal or non-metal 3. Comparison of element properties (metal and non-metal) with neighboring elements by period and group. 4. Write the distribution of electrons in atomic orbitals - a quantum diagram. Write an electronic formula. 5. Sketch the distribution of electrons by energy levels 6. Determine the highest oxidation state of an atom and the formula of its highest oxide. Determine the nature of the oxide (basic, acidic, amphoteric). 7. Determine the lowest oxidation state of the element and the formula of its hydrogen compound (if any).

Homework §1, answer the questions. Using the characteristic plan of a chemical element, characterize B, C, Si, Rb, Sr, Br. Do not forget that if an element is in the main subgroup, then we compare it only with the elements of the main subgroup.

On the topic: methodological developments, presentations and notes

System-activity approach in the study of chemistry. Grade 9 Characteristics of an element by its position in the periodic system.

The description of the first lesson of grade 9 in chemistry on the topic "Characteristics of an element by its position in the periodic system" is given. The lesson is given using a system-activity approach, using different...

Characteristics of a chemical element and its compounds based on the position in the Periodic system and the structure of the atom

summary of a chemistry lesson in grade 9 ...

A plan for the characteristics of a chemical element-metal based on its position in the PSCE D.I. Mendeleev.

Synopsis of a lesson in chemistry of the 9th grade. Type of lesson: a lesson of generalization and systematization of the acquired knowledge. ...

Summary of a lesson in chemistry

in 9th grade

"Characteristics of the chemical element-metalon the basis of its position in the Periodic system of D. I. Mendeleev.

Lesson topic:Characteristics of the chemical element-metal based on its position in the Periodic system of D. I. Mendeleev. (1 slide)

Lesson Objectives:update knowledge about the structure of the periodic system,

to systematize knowledge about the composition and structure of the atom of an element,

be able to characterize an element based on its position in the periodic system, systematize knowledge about the composition and properties of compounds formed by metals (2 slide)

Equipment:Table D. I. Mendeleev. Simple substances - metals and non-metals, computer, projector, presentation on the topic.

The course and content of the lesson

I. Organizing time

Greetings from the teacher. Congratulations to the children on the start of the new school year.

P. Repetition of the main theoretical issues of the 8th grade program

The main issue of the 8th grade program is the Periodic system of chemical elements of D. I. Mendeleev. It is also the basis for studying the 9th grade chemistry course.

I remind you that the table of D. I. Mendeleev is a “house” in which all chemical elements live. Each element has a number (serial), which can be compared with the number of the apartment. The "apartment" is located on a certain "floor" (i.e. period) and in a certain "entrance" (i.e. group). Each group, in turn, is divided into subgroups: main and secondary. Example: the element magnesium mg has serial number (No.) 12 and is located in the third period, in the main subgroup of the second group.

The properties of a chemical element depend on its position in the table of D. I. Mendeleev. Therefore, it is very important to learn how to characterize the properties of chemical elements based on their position in the Periodic system.

III. Plan for the characteristics of a chemical element based on its position in the Periodic system of D. I. Mendeleev

Characterization algorithm: (3-5 slides)

1. The position of the element in the PS

a) the serial number of the chemical element

b) period (large or small).

c) group

d) subgroup (main or secondary)

e) relative atomic mass.

2. Composition and structure of the atom of the element

a) the number of protons (p +), neutrons ( n 0 ), electrons (e -)

b) nuclear charge

in ) the number of energy levels in an atom

d) the number of electrons in the levels

e) the electronic formula of the atom

f) graphic formula of the atom

g) element family.

The last three points are for well prepared classes.

3. Properties of the atom

a) the ability to donate electrons (reducing agent)

b) the ability to accept electrons (oxidizer).

Write in the form of schemes-equations. Compare with neighboring atoms.

4. Possible degrees of oxidation.

5. Formula of higher oxide, its character.

6. Formula of higher hydroxide, its character.

7. Formula of a volatile hydrogen compound, its nature.

Note: When considering points 5 and 7, all the formulas of higher oxides and volatile hydrogen compounds are placed at the bottom of the table of D. I. Mendeleev, which is actually a “legal cheat sheet”.

Since at the beginning, when characterizing the elements, the guys may experience certain difficulties, so it is useful for them to use “legal cheat sheets” - table. 1 and others. Then, as experience and knowledge are accumulated, these assistants will no longer be required.

Exercise: Describe the chemical element sodium based on its position in D.I. Mendeleev. (slide 6)

The whole class works, students take turns taking notes on the board.

Sample response. (slide 7)

Na– sodium

1) 11, 3 period, small, 1 group, A

2) 11 R + ,12n 0 , 11e -

+ 112-8-1

1s 2 2s 2 2p 6 3s 1 3p 0 3d 0 - s - element

3) Na 0 – 1 e > Na +

reducing agent

Ra:Li mg

by groupby period

Me sv-va:Li< Na < K Na > mg

by groupby period

4) Na:0, +1

5) Na 2 O- basic oxide

6) NaOH- base, alkali.

7) Does not form

IV. Plan for the characteristics of a simple substance.

Each chemical element forms a simple substance with a specific structure and properties. A simple substance is characterized by the following parameters: (slide 8)

1) Communication type.

2) Type of crystal lattice.

3) Physical properties.

4) Chemical properties (scheme).

Answer Sample :(slide 9)

Metal bond[Na 0 – 1 e > Na + ]

- Metal crystal lattice

- Solid, soft metal (cut with a knife), white, lustrous, thermally and electrically conductive.

Show metal. Note that due to the high chemical activity, it is stored under a layer of kerosene.

- Na 0 – 1 e > Na + > interacts with oxidizing agents

reducing agent

Non-metals + metal oxides (less active)

Acids + salts

Water

Exercise : Write down the reaction equations that characterize the properties of a simple substance sodium. Consider the equations from the standpoint of redox processes. (Slide 10)

Five students volunteer to work at the blackboard.

Answer:

1) 2 Na + Cl 2 > 2 NaCl

Na 0 – 1 e > Na +

Cl 2 0 + 2 e > 2 Cl - ¦1 oxidizing agent - reduction

2) 2 Na + 2 HCl > 2 NaCl + H 2

Na 0 – 1 e > Na + ¦2 reducing agent - oxidation

2 H + + 2 e > H 2 0 ¦1 oxidizing agent - reduction

3) 2 Na + 2 H 2 O > 2 NaOH + H 2

Na 0 – 1 e > Na + ¦2 reducing agent - oxidation

2 H + + 2 e > H 2 0 ¦1 oxidizing agent - reduction

4) 2 Na + MgO > Na 2 O + Mg

Na 0 – 1 e > Na + ¦2 reducing agent - oxidation

Mg 2+ + 2 e > Mg 0 ¦1 oxidizing agent - reduction

5) 2 Na + CuCl 2 (melt) > 2 NaCl + Cu

Na 0 – 1 e > Na + ¦2 reducing agent - oxidation

Cu 2+ + 2 e > Cu 0 ¦1 oxidizing agent - reduction

V. Connection characteristics plan.

Each chemical element is characterized by the formation of complex substances of various classes - oxides, bases, acids, salts. The main parameters of the characteristics of a complex substance are: (slide 11)

Connection formula.

Communication type.

The nature of the connection.

Chemical properties of the compound (scheme).

Sample response:

I . Oxide (slide 12)

1) Na2O

2) Ionic bond

3) Salt-forming, basic oxide.

4) Chemical properties:

· basic oxide + acid > salt and water

· basic oxide + acid oxide > salt

· basic oxide + H 2 O> alkali

(soluble oxide)

II. Hydroxide (slide 13)

1) NaOH

2) Ionic bond

3) Base, alkali.

4) Chemical properties:

base (any) + acid = salt + water

alkali + salt = new base + new salt

alkali + non-metal oxide \u003d salt + water

Independent work.

Exercise: Write down the reaction equations characterizing the properties of the oxide and hydroxide. The equations are considered from the positions of redox processes and ion exchange. (slide 14)

Sample answers.

Sodium oxide:

l) Na 2 O + 2 HC 1 \u003d 2 NaCl + H 2 O (exchange reaction)

2) Na 2 O + SO 2 = Na 2 SO 3 (compound reaction)

3) Na 2 O + H 2 O \u003d 2 NaOH (compound reaction)

Sodium hydroxide:

1) 2 NaOH + H 2 SO 4 \u003d Na 2 SO 4 + 2H 2 O (exchange reaction)

2 Na + + 2OH - + 2H + + SO 4 2- \u003d 2 Na + + SO 4 2- + 2H 2 O

OH - + H + \u003d H 2 O

2) 2 NaOH + CO 2 \u003d Na 2 CO 3 + H 2 O (exchange reaction)

2 Na + + 2OH-+ CO 2 \u003d 2 Na + + CO 3 2- + H 2 O

3) 2NaOH + CuSO 4 = Na 2 SO 4 + Cu (OH) 2 ( exchange reaction)

2Na + + 2 OH - + Cu 2+ + SO 4 2- = 2Na + + SO 4 2- + Cu (OH) 2

2 OH - + Cu 2+ \u003d Cu (OH) 2

Recall the conditions for the flow of exchange reactions to the end (formation of a precipitate, gas or weak electrolyte).

For sodium, as for all metals, the formation of a genetic series is characteristic: (slide 15)

Metal > basic oxide > base (alkali) > salt

Na > Na 2 O > NaOH > NaCl (Na 2 SO 4, NaNO 3, Na 3 PO 4)

Homework (slide 16)

§ 1, ex. 1 (b), 3; compose reaction equations for the genetic series Na