chemistry lesson

Introduction to General chemistry

Lesson objectives: to familiarize students with the tasks and structure of the chemistry course in grade 11; to repeat and generalize knowledge of students on the subject chemistry, matter, atom, basic atom structure, Periodic law, Periodic system of chemical elements D. I. Mendeleev (hereinafter PSHE), chemical bonds purchased in the chemistry course in 8th grade.

Equipment: tables of the chemistry course of the 8th grade ("structure of the atom", "Chemical bond"), PSE.

Lesson progress

I. Organizational moment

At the beginning of the school year, students are given introductory instructions on occupational health and safety in the chemistry room (hereinafter referred to as OT and TB). It is necessary to remind students of the basic rules of behavior in the chemistry room when conducting laboratory and practical work, and the rules for working with the notebook "Instructing OT and TB".

The chemistry class 11 course is structured logically: from studying the composition and structure of an atom to studying the composition and structure of substances, then an in-depth study of chemical reactions, and then the study of chemical properties of substances, their preparation and application.

Students for a more in-depth study of the topic " Structure of the atom. Pshe D. I. Mendeleev" it is necessary to remember the following:

a) the concepts of "substance", "atom", "chemical element", " isotope»;

b) elementary composition of an atom, electronic structure of an atom, electron-graphic structure of an atom;

C) the structure of the Mendeleev PSC;

d) metal and nonmetallic elements, their change in theirproperties STV in SVyazy with the position in the system of chemical elements;

e) chemical bond, types of chemical bond.

Students are asked to complete the test tasks. The tasks of the theoretical part of the test are discussed together with the teacher, the practical part is performed independently according to the options.

II. Conducting the test

Theoretical part

1. Remember the definition of an atom.

2. What is the structure of an atom?

3. What elementary particles are part of the nucleus of an atom? How is the charge of the nucleus of an atom determined?

4. What determines the amount of protons and neutrons?

5. Give the definition of a chemical element.

6. How to determine the number of protons, neutrons and electrons in an atom? Prove that an atom is an electroneutral particle.

7. give a definition of the isotope.

8. What is the structure of the electron shell of an atom? How is the number of electrons in it determined?

9. How to determine the maximum number of electrons at the energy level?

10. How is the number of electrons at the external energy level determined?

11. What is an orbital? What shape do the s - and p-orbitalshave ? Which electrons are called s-and p-electrons?

12. What is an electronic formula?

13. How and why do the properties of chemical elements change within a given range:

a) one period;

b) a group, the main subgroup when the charge of the nucleus of an atom increases?

14. Describe the ways to complete the last energy level:

a) characteristic of the metal element;

b) characteristic of a non-metallic element.

15. What types of chemical bonds are you familiar with?

16. What is the reason for different types of chemical bonding?

Practical part

III. Homework assignment

Repeat the information about the structure of the atom (§ 4-12) according to the textbook of X class.

Answers to the test questions

Theoretical part

1. Atom — the smallest particle of matter, chemically indivisible; "atom" - means "indivisible".

2. the Atom has a complex structure. It consists of a positively charged nucleus and electrons.

3. the nucleus of an atom consists of: protons having mass 1 and charge +1; neutrons having mass 1 and charge 0; the charge of the nucleus is determined by the number of protons.

4. the Sum of protons and neutrons corresponds to the mass number of an atom — the mass of an atom.

5. Chemical element — a type of atom with a certain charge of the nucleus.

6. The index of the item in PSHA corresponds to the number of protons in the nucleus of the atom, number of electrons in the atom, so the atom — alternately particle; the number of neutrons is determined by the difference between the mass number and number of protons.

7. Isotopes — chemical elements that have the same nuclear charge, but different atomic mass.

8. the Number of electrons is determined by the ordinal number of the element. The electron shell of an atom consists of a certain number of energy levels. The number of energy levels in an atom corresponds to the period number of a chemical element.

9. the Maximum number of electrons is determined by the formula: 2n², where n is the number of the energy level.

10. the Number of electrons at the external energy level of an atom of a chemical element is determined by the number of the PSE group.

11. Orbital — the space around the nucleus of an atom, where the greatest probability of finding electrons. S-orbital has the shape of a sphere (globe), p-orbital has the shape of a surround of eight s-electrons located in s-orbitalsand p-electrons located in p-orbitals.

12. Electronic formula-a record of the structure of an atom, which indicates the energy levels, orbitals at energy levels and the number of electrons in the orbitals. It should be remembered that the maximum number of electrons in the s-orbital is 2, in the p-orbital-6; at the first energy level , the j -orbitalopens, at the second energy level, the s - and p -orbitals.

13. Within a period with increasing charge of the nucleus of an atom, increasing the number of electrons in the outer energy level decreases the radius of the atom, resulting in increases nemetallicheskie — the ability to accept electrons.

In groups, the main subgroups, the number of energy levels increases with the growth of the atom's charge, the atomic radius increases, resulting in increased metallicity — the ability to give up electrons.

14. the Last energy level of the metal atom is far from complete, until the stability of the metal atom is energetically profitable to give the electrons of the external energy level; the last energy level of the nonmetal atom is close to completion, it is energetically profitable for the nonmetal atom to take the missing electrons to the stability of the energy level.

15. Covalent bond polar and nonpolar, ionic bond, metal bond.

16 .electronegativity is the Cause of various types of bondingэлектроотрицательность. Electronegativity — the ability of atoms to attract missing electrons to the last energy level. In the case of a sharp difference in the electronegativity of atoms, an ionic bond occurs; covalent polar coupling occurs between atoms that do not differ sharply in electronegativity; in the case of identical electronegativity of atoms, a covalent nonpolar bond occurs.

Practical part