Theme: Simple and complex substances. Chemical element.
About atoms and chemical elements
There is nothing else in nature
neither here nor there, in the depths of space:
everything - from small grains of sand to planets -
of the elements consists of a single.
S. P. Shchipachev, "Reading Mendeleev."
In chemistry, in addition to the terms "atom" and "molecule", the concept of "element" is often used. What is common and how do these concepts differ?
Chemical elementare atoms of the same type.So, for example, all hydrogen atoms are the element hydrogen; all oxygen and mercury atoms are the elements oxygen and mercury, respectively.
Currently, more than 107 types of atoms, that is, more than 107 chemical elements, are known. It is necessary to distinguish between the concepts of “chemical element”, “atom” and “simple substance”
Simple and complex substances
By elemental composition, simple substances are distinguished, 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, which form about 500 simple substances.
Native gold is a simple substance.
The ability of one element to exist in the form of various simple substances that differ in properties is called allotropy. For example, the element oxygen O has two allotropic forms - dioxygen O2 and ozone O3 with a different number of atoms in the molecules.
The allotropic forms of the element carbon C - diamond and graphite - differ in the structure of their crystals. There are other reasons for allotropy.
Element name
Allotropic forms
Carbon C
Graphite
Diamond
Complex substances are often called chemical compounds, for example, mercury (II) oxide HgO (obtained by combining atoms of simple substances - mercury Hg and oxygen O2), sodium bromide (obtained by combining atoms of simple substances - sodium Na and bromine Br2).
So let's summarize the above. Molecules of matter are of two types:
1. Simple - the molecules of such substances consist of atoms of the same type. In chemical reactions, they cannot decompose with the formation of several simpler substances.
2. Complex - the molecules of such substances are composed of atoms different kind. In chemical reactions, they can decompose to form simpler substances.
The difference between the concepts of "chemical element" and "simple substance"
The concepts of “chemical element” and “simple substance” can be distinguished by comparing the properties of simple and complex substances. For example, a simple substance - oxygen - a colorless gas necessary for breathing, supporting combustion. The smallest particle of a simple substance oxygen is a molecule that consists of two atoms. Oxygen is also included in carbon monoxide ( carbon monoxide) and water. However, the composition of water and carbon monoxide 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, do not breathe chemically bound oxygen, which is part of the water molecule, but free, dissolved in it. That's why when we are talking about the composition of any chemical compounds, it should be understood that these compounds do not include simple substances, but atoms of a certain type, that is, the corresponding elements.
When complex substances are decomposed, atoms can be released in a free state and combined to form simple substances. Simple substances are made up of atoms of one element. The difference between the concepts of "chemical element" and "simple substance" is also confirmed by the fact that one and the same element can form several simple substances. For example, atoms of the element oxygen can form diatomic oxygen molecules and triatomic ozone molecules. Oxygen and ozone are completely different simple substances. This explains the fact that much more simple substances are known than chemical elements.
Using the concept of "chemical element", we can give the following definition of simple and complex substances:
Simple substances are substances that consist of atoms of one chemical element.
Substances that are composed of atoms of different chemical elements are called complex.
The difference between the concepts of "mixture" and "chemical compound"
Complex substances are often called chemical compounds.
Try to answer the questions:
1. What is the difference in the composition of the mixture from chemical compounds?
2. Compare the properties of mixtures and chemical compounds?
3. In what ways can a mixture and a chemical compound be divided into constituent components?
Comparative characteristics mixtures and chemicals
Questions for comparing mixtures with chemical compounds
Mapping
Mixes
Chemical compounds
How do mixtures differ from chemical compounds in composition?
Substances can be mixed in any ratio, i.e. the composition of mixtures is variable
The composition of chemical compounds is constant.
Compare the properties of mixtures and chemical compounds?
Substances in mixtures retain their properties
Substances that form compounds do not retain their properties, since chemical compounds with different properties are formed.
How can a mixture and a chemical compound be separated into its constituent components?
Substances can be separated by physical means
Chemical compounds can only be decomposed by chemical reactions
Is it possible to judge outward signs about the formation of a mixture and a 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 signs of chemical reactions
II. Solve the task
From the proposed list of substances, write out 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 written in a series of formulas:
H2O, N2, O3, HNO3, P2O5, S, Fe, CO2, KOH.
№2
Both substances are 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 the correct statement:
Simple substances are made up of atoms of the same kind.
A) right
B) False
№4
Mixtures are characterized by
A) they have a constant composition;
B) Substances in the "mixture" do not retain their individual properties;
C) Substances in "mixtures" can be separated physical properties;
D) Substances in "mixtures" can be separated by a chemical reaction.
№5
For "chemical compounds" the following is typical:
A) Variable composition;
B) Substances in the composition of a "chemical compound" can be separated by physical means;
C) The formation of a chemical compound can be judged by the signs of chemical reactions;
D) permanent composition.
№6
In what case is it about iron as a chemical element?
A) Iron is a metal that is attracted by a magnet;
B) Iron is part of the composition of rust;
C) Iron has a metallic luster;
D) Iron sulfide contains one iron atom.
№7
In which case is oxygen referred to as simple matter?
A) Oxygen is a gas that supports respiration and combustion;
B) Fish breathe oxygen dissolved in water;
C) The oxygen atom is part of the water molecule;
D) Oxygen is present in the air.
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Key words of the abstract: state of aggregation of substances, crystal lattice, substances of molecular and non-molecular structure, simple and complex substances.
Substances can only exist in three aggregate states: gaseous, liquid and solid.
In the gaseous state, matter exists in the form of individual particles (molecules, atoms, or ions). The distance between particles in gases is much greater than the size of these particles. In liquids, the distance between individual particles is much smaller, so the forces of mutual attraction between them are much greater than in gases. While the particles that make up solid(atoms, molecules or ions) are densely packed and perform oscillatory movements. Distinguish crystalline and amorphous solid bodies.
For crystalline substances characterized by an ordered arrangement of the particles of which they are composed. For example, a snowflake has a perfect shape due to the fact that the water molecules of which it is composed are ordered in relation to each other. The correct shape of the crystals is due to the peculiarities of their internal structure. In crystals, they are arranged in a certain order, at certain distances from each other.
The set of points in space in which the particles that form the crystal are located is called the CRYSTAL LATTICE.
Substances that are made up of molecules are substances of molecular structure. Substances that are made up of atoms or ions are non-molecular substances.
Substances with a molecular and non-molecular structure differ significantly in their properties. To melt a substance, it is necessary to destroy its crystal lattice. It turns out that in a crystal lattice the bonds between molecules are much weaker than the bonds between atoms or ions. Therefore, as a rule, substances with a molecular structure have low temperatures melting and boiling. Such substances are often volatile and have an odor.
Substances with a non-molecular structure have high melting and boiling points. These substances are solid, non-volatile and odorless.
Simple and complex substances
Complex Substances- These are substances that are formed by atoms of different types. For example, such a complex substance as water consists of oxygen and hydrogen atoms, carbon dioxide consists of carbon and oxygen atoms.
Substances such as sulphur, iron, oxygen and hydrogen, for example, can neither be obtained from simpler substances nor decomposed. These substances are classified only as simple substances.
Simple substances are substances that are formed by atoms of the same type. For example, a simple substance oxygen consists of only oxygen atoms, a simple substance graphite - only from carbon atoms.
Department of Education Management
Svobodnensky district of the Amur region
MOU Rogachevskaya OOSh
Subject:
"Simple and Complex Substances"
Chemistry Grade 8
Teacher I Categories: Anchukhina T.S.
with. Rogachevka
Target: familiarization with simple and complex substances - the main forms of the existence of elements in nature; performance of tasks for the assimilation of the concepts of "simple substance", "complex substance",Develop skills to distinguish simple substances from complex ones, based on their chemical formulas.
Lesson objectives
educational : 1. to reveal the concepts: simple and complex substances as a form of existence of chemical elements
Developing: 1.Develop cognitive interest to the subject being studied; 2. create conditions for mastering the methods of studying the composition of matter; 3.fto form the ability to search, process, analyze and systematize information; 4. pdevelop the ability to logically express their point of view; 5. teach reflection techniques, develop adequate self-esteem; 6. develop the ability to receive information.
Educational:independently solve problems using existing knowledge; develop the ability to analyze, compare, compare and generalize;learn to be independentin different types of activities;
Planned results.
1. Formation of ideas about the forms of existence of chemical elements in nature and the development of knowledge about chemical elements.
2. Development of students' knowledge about the physical properties of substances.
3. Development of scientific thinking of students in the formation of skills to compare and describe chemical objects in the course of independent performance of exercises and complex tasks, as well as in the development of skills to apply knowledge and methods of action in new conditions.
4. The formation of the scientific worldview of schoolchildren and the assimilation of the leading worldview ideas of the course: the cognizability and unity of the material world, the dependence of the properties of substances on its composition and structure.
5. Development of interest and motivation for studying chemistry when referring to the life experience of schoolchildren and systematizing knowledge about the distribution and relationship of substances in nature.
During the classes:
Hello! Hello dear guests!
Why are you so saddened in chemistry class?
Tell me quickly: in which lesson,
Who dared to offend you in the near past?
So I will lift your spirits today,
I know the most The best way:
Let's explore the topic!
2 . Checking homework.
Traditionally again
We start as usual
We check homework.
It's habitual for us.
Get ready to answer
Now I will call!
Scared? I joked…
I will not call!
Better tests I will give you
I'll give you all grades later.
Exercise 1. In the table, write the letter “X” or “F” (chemical or physical) against each phenomenon, and the letters “T” or “T” against bodies and substances.
"B" respectively .
P/n
Task2. Define the terms "molecule" and "atom".
Task 3. Determine the composition: H 2 O, O 2 , CO 2, Cl 2.
3. Learning new material.
In chemistry, in addition to the terms "atom" and "molecule", the concept of "element" is often used. What is common and how do these concepts differ?A chemical element is an atom of the same kind. So, for example, all hydrogen atoms are the element hydrogen; all oxygen and mercury atoms are the elements oxygen and mercury, respectively.O 2 , Cl 2. H 2 O, CO 2
How are oxygen and chlorine molecules different from water and carbon dioxide molecules? Students can answer that oxygen and chlorine molecules are formed by atoms of the same type. – Simple substances.Substances water and carbon dioxide are formed by atoms of different types. - Complex substances.Simple substances - substances formed by atoms of one chemical element.
Ne, Ar, O 2 , Br 2 , I 2 ,O 3 , P 4 , S 8
(Monatomic simple substances are molecules of inert gases; diatomic - molecules of hydrogen, oxygen, chlorine, bromine, iodine; triatomic - ozone, tetraatomic - phosphorus, etc.)
The names of simple substances often coincide with the name of the CE, the atoms of which they are formed.
Simple substances are characterized by certain physical properties ( state of aggregation, color, density).
compound substances ( chemical compounds) - These are substances formed by atoms of different chemical elements interconnected.
H 2 O, C 6 H 12 O 6 , NaCl, KMnO 4 , CO 2 , CO
(water, glucose, sodium chloride - salt, potassium permanganate - potassium permanganate, carbon dioxide, carbon monoxide).
Complex substances are characterized by certain physical properties.
SUBSTANCES
simple complex
H 2 ,O 2 , N 2 , Cl 2 H 2 Oh, CO 2 , H 2 SO 4
Fixing the topic “Simple and complex substances. Relative molecular weight of a substance.
Exercise. Divide the following substances into simple and complex: SO 2 K , Cu , N 2 , O 2 , Cl 2 , Al 2 O 3 , H 2 , Br 2 , NaCl , MgSO 4 , KOH , Fe , Au , Ag , ZnO , LiI KF , Cr , SO 3
Present the result in the form of a table:
SIMPLE SUBSTANCES
Calculate molecular weights substances (independently with verification).
Test.
№1
How many simple substances are written in a series of formulas:
H 2 O, N 2, O 3, HNO 3, P 2 O 5, S, Fe, CO 2, KOH.
№2
Both substances are complex:
A) C (coal) and S (sulfur);
B) CO 2 (carbon dioxide) and H 2 O (water);
B) Fe (iron) and CH 4 (methane);
№3
Choose the correct statement:
Simple substances are made up of atoms of the same kind.
A) right
B) False
№4
In what case is it about iron as a chemical element?
A) Iron is a metal that is attracted by a magnet;
B) Iron is part of the composition of rust;
C) Iron has a metallic luster;
D) Iron sulfide contains one iron atom.
№5
In what case is it about oxygen as a simple substance?
A) Oxygen is a gas that supports respiration and combustion;
B) Fish breathe oxygen dissolved in water;
C) The oxygen atom is part of the water molecule;
D) Oxygen is present in the air.
Perform practical tasks in the form of independent work.
Reflection and summing up. What new did you learn in the lesson?What questions caused difficulty?What knowledge have you acquired today?Homework. §5, 6 p. 25 exercise no. 11–13
Examples of a practical task:
Instead of dots, insert the necessary expressions (chemical element, simple substance, complex substance, mixture): a) copper oxide ______________, since it consists of _______________________, copper and oxygen; When ____________________ mercury oxide is heated, two ___________________________ are formed: mercury and oxygen.
Fill in the missing words: a) the composition of chemical compounds ___________________ structure _______________________________.
b) substances that are part of mixtures ______________________________ only with the help of _______________________.
c) mechanical mixing _____________________ by the release of heat or other signs of chemical reactions.
Subject: Simple and complex substances. Chemical element.
Developed by: Teryukova Elena Alexandrovna
biology and chemistry teacher
with. Arkhangelsk. Voronezh region
Lesson Objectives: to study the concepts of "simple and complex substance", "chemical element", "allotropy";
Learn to recognize simple and complex substances, learn how to make a comparative description of a “mixture” and a “chemical compound”
- educational: formulate a clear idea of \u200b\u200ba simple and complex substance, a chemical element, define the concept of "allotropy";
- developing: to form the ability to extract information from an oral message, video fragments, presentations, observed processes; describe observations, depict schematically devices;
to form the ability to analyze data, identify the essence of the observed processes, generalize and draw conclusions;
develop the ability to formulate and argue own opinion, develop independence;
continue the formation of the chemical speech of students, creative thinking, the rules of scientific communication, the ability to predict the result of activity;
organize independent activities, improve the skills of self-assessment of knowledge
- educators: foster a culture of intellectual work; sense of responsibility, self-confidence, exactingness to oneself; ability to work in pairs.
Planned results:
Subject: know clearly what “simple and complex substance”, “chemical element”, “allotropy” is.
Be able to identify the distinguishing features of a "mixture" and a "chemical compound". Mastering the conceptual apparatus of the lesson;
gaining experience in using various methods for studying chemical phenomena: observing their transformations during simple chemical experiments using laboratory equipment and instruments;
the ability to conduct and describe independently performed chemical experiments using native language and the language of chemistry;
the ability to draw conclusions and conclusions from observations, studied chemical patterns.
Metasubject:
Regulatory UUD
the ability to correlate their actions with the planned results, monitor their activities in the process of achieving the result, determine the methods of action within the framework of the proposed conditions and requirements, adjust their actions in accordance with the changing situation, evaluate the results of solving the tasks set, etc.
Cognitive UUD
A clear idea of \u200b\u200b"simple and complex substances", "chemical element", "allotropy"; put them into practice.
the ability to create, apply and transform signs and symbols, models and schemes for solving educational and cognitive tasks;
the use of basic intellectual operations: analysis and synthesis, comparison, generalization, identification of cause-and-effect relationships, search for analogues;
formation and development of competence in the use of information and communication technologies (ICT competencies);
use of various sources to obtain chemical information;
setting and formulating the purpose and objectives of the lesson; formulation and argumentation of personal opinion
Communicative UUD
consciously and voluntarily build a speech statement in oral form; reasoned answer questions, justify their point of view; listen and understand the speech of others; enter into educational cooperation with the teacher and classmates, carry out joint activities in pairs, groups, etc.
Equipment:
multimedia projector;
multimedia presentation for the lesson;
laboratory equipment;
Lesson structure:
organizational stage.
Knowledge update.
Statement of the educational task.
Assimilation of new knowledge and primary consolidation.
Fizkultminutka.
Consolidation of the studied material.
Homework.
During the classes:
Lesson stages
Formed Skills
Teacher activity
Student activities
1. Organizational moment.
Target:
Creating a working mood of students for the lesson, motivation for learning. Determine the level of preparation of students for the lesson
Personal:
define general and individual rules of work for all
Metasubject:
Regulatory UUD
the ability to exercise control over one's activities, determine methods of action and correct them
Communicative UUD
listen and understand the speech of others
Greetings. Checking the readiness of the class and the classroom for the lesson. Missing. I inform you that we have a lesson in learning new material.
Preparation for checking homework.
Checking home
tasks.
Exercise 1.
1.) What are atoms?
2.) What are molecules?
3.) What is the crystal lattice of a substance?
4.) Substances of molecular structure are…….
5.) Substances of non-molecular structure are ......
Task 2.
History of the study of the structure of matter. Scientists and their works.
Task 3.
List the types of crystal lattices. Describe the physical properties of substances characteristic of each type of crystal lattice.
Task 4.
Give examples of substances with different crystal lattices.
Teacher greeting. Checking the workplace: the location of educational supplies, the availability of handouts, laboratory equipment.
Prepare for assignments.
Complete tasks on an individual basis.
2.Updating knowledge.
Target: leading students to the question: “Why do we need knowledge about simple and complex substances, chemical elements and the phenomenon of allotropy?”
Personal : The ability to observe discipline in the classroom, respectfully treat the teacher and classmates. Formation of an idea about the need to study the subject of chemistry, the need to gain knowledge about simple and complex substances, a chemical element, the phenomenon of allotropy. Application of knowledge in practice.
Regulatory UUD:
Ability to organize the implementation of tasks of the teacher.
Communicative UUD: ability to perceive information by ear, answer questions from the teacher
In the last lesson, we recalled the history of studying the structure of substances. They talked about the works of Leucippus, Democritus, Lomonosov.
Here we can add the works of the French scientists Boyle and Mariotte, who confirmed the existence of the smallest particles of matter. It remained only to understand what these particles are.
Over the next 150 years, after the work of Boyle and Mariotte, the efforts of chemists were directed to establishing the composition various substances.
And scientists have succeeded in this. Let's try it too.
3. Statement of the educational task.
Target:
Motivate students to learn new knowledge.
Defining the goals and objectives of the lesson
Personal:
formation of readiness and ability of students for self-development and self-education
Metasubject:
Communicative UUD
consciously and voluntarily build a speech statement in oral form; reasoned answer questions, justify their point of view; listen and understand the speech of others
Regulatory UUD:
accept the educational and cognitive task and keep it until the end of the educational activities;
correct your own answers and the answers of classmates
Cognitive UUD:
setting and formulating the purpose and objectives of the lesson; formulation and argumentation of personal opinion;
awareness of the educational and cognitive task
In nature there is great amount substances.
We found out that substances are made up of atoms and molecules.
Atoms, under normal conditions, cannot exist alone for a long time. They are able to combine with the same or other atoms.
What is the result?
How can one explain the great diversity of substances in nature?
How do you think, into what points can substances be divided by composition?
A set of atoms with the same or similar characteristics is ... ..?
Trying to answer the questions, please try to formulate the purpose and objectives of our lesson.
Conclusion: in the course of today's lesson, we will learn what results from the combination of atoms, how substances are separated by composition, what a chemical element is. We learn about such a phenomenon as "allotropy".
Let's apply the acquired knowledge in practice.
Students listen to the teacher, perceive information.
They are trying to answer questions.
Formulate the goals and objectives of the lesson.
They draw conclusions.
4. Learning new material.
Target:
To study the concepts of "simple and complex substance". "chemical element", "allotropy";
To study the distinguishing characteristics of a "mixture" and a "chemical compound".
Personal:
ability to manage your cognitive activity; determine general and individual rules of conduct;
formation of a responsible attitude to learning, readiness and ability of students for self-development and self-education based on motivation for learning and cognition, conscious choice and building a further individual trajectory of education;
formation communicative competence in communication and cooperation with peers, adults in the process of educational, teaching and research activities
Metasubject:
Regulatory UUD
the ability to correlate one's actions with the planned results, to control one's activities in the process of achieving the result, to determine the methods of action within the framework of the proposed conditions and requirements, to adjust one's actions in accordance with the changing situation, to evaluate the results of solving the tasks set
Cognitive UUD
Give a precise definition of the concepts of "simple and complex substance", "chemical element", "allotropy". Be able to clearly distinguish mixtures from chemical compounds,the ability to create, apply and transform signs and symbols, models and schemes for solving educational and cognitive problems;
the use of basic intellectual operations: analysis and synthesis, comparison, generalization, identification of cause-and-effect relationships, search for analogues;
formation and development of competence in the use of information and communication technologies (ICT-competencies)
Communicative UUD
consciously and voluntarily build a speech statement in oral form; reasoned answer questions, justify their point of view; enter into educational cooperation with the teacher and classmates, carry out joint activities in pairs, groups
Subject:
mastering the conceptual apparatus of the lesson
Teacher's story.
atoms different substances connected with each other in a strictly defined order, the establishment of which is one of the most interesting activities chemist.
Scientists of the past, substances that decomposed into simpler ones were called “compounds (complex substances), for example, water (remember the previous lesson - water electrolysis), carbon dioxide, iron oxide. Substances that could not be further decomposed were called "elements" (simple substances), for example: hydrogen, oxygen, copper, gold.
Compiling a cluster:
Substances
Simple Complex
Compounds are often calledchemical compounds.
Example: mercury oxide (2) is obtained by combining atoms of simple substances - mercury and oxygen.
The number of different substances is enormous. There are relatively few atoms in the material world around us, differing from each other in their most important characteristics - about a hundred. Each type of atom has its own chemical element.
Chemical element is a collection of atoms with the same or similar characteristics.
There are about 90 different chemical elements found in nature. By now, physicists have learned how to create new, missing kinds of atoms. Such atoms (and, accordingly, such chemical elements) are calledartificial.
To date, more than 2 dozen artificially obtained elements have been synthesized.
Each element has a Latin name and a one- or two-letter symbol.
Compiling a table:
Compiling a cluster:
"Forms of existence of a chemical element".
Chemical element
Free atoms Compound substances
Simple substances
Simple substances are substances that are made up of atoms of a single chemical element.
Complex Substances Substances that are made up of atoms of various chemical elements.
One of the first chemists who pointed out the need to distinguish between the concepts of a simple substance and a chemical element was D.I. Mendeleev. Indeed, each simple substance is characterized by certain physical and chemical properties. When any simple substance enters into chemical reaction and forms a new substance, then it loses most of its properties. Example: iron, reacting with sulfur, loses its metallic luster, malleability, and magnetic properties.
The distinction between a simple substance and an element becomes especially clear when we encounter several simple substances that are composed of the same chemical element.
Example: a piece of phosphorus is a white translucent substance with a melting point of 44.2 about C, very poisonous, in air, in the dark, phosphorus glows and can ignite spontaneously.
Phosphorus is a simple substance, it cannot be decomposed into other substances.
But, if phosphorus is heated without access to air, it acquires a glow in the dark, becomes non-toxic, does not ignite spontaneously in air, and these new properties do not disappear when heating is stopped.
At the same time, the substance we have taken does not decompose, nothing is added to it, but a different form of the existence of the same element in a free state is observed:
The 1st substance is white phosphorus, the 2nd substance is red phosphorus.
Like phosphorus, many other elements in the free state can exist in the form of various simple substances.
The existence of a chemical element in the form of several simple substances is calledallotropy.
Different simple substances formed by the same element are calledallotropic modifications this element.
Example: O2 and O3;
Carbon: graphite, diamond, carbine, graphene.
Phosphorus: white, red, black.
Sulfur: rhombic, monoclinic, plastic.
Drawing up a table: "Comparative characteristics of mixtures and chemical elements."
(Appendix 1).
Students listen to the teacher, perceive information.
Write the definition in a notebook.
Make up a cluster.
Write down the definitions.
Fill out the table.
5. Physical education minute.
Eye exercises.
Perform exercises.
6. Fixing the material.
Target: generalization and systematization of the acquired knowledge.
Personal UUD:
The ability to manage their cognitive activity.
Regulatory UUD:
The ability to exercise control over their activities in the process of achieving results.
Solution of practical tasks.
(Appendix 2).
Grading.
Perform tasks.
Participate in discussions, complement each other, analyze answers.
Clean up the workplace.
7. Homework.
Write down homework.
MUNICIPAL BUDGET GENERAL EDUCATIONAL INSTITUTION
"TAURIAN SCHOOL-GYMNASIUM No. 20"
OF THE MUNICIPALITY OF THE CITY DISTRICT OF SIMFEROPOL OF THE REPUBLIC OF CRIMEA
Subject:
"Simple and Complex Substances"
Chemistry Grade 8
TeacherICategories: Rymarchuk O.V.
Simferopol, 2016
Lesson #10
Topic: "Simple and complex substances"
The purpose of the lesson: explain the difference between a simple substance and a complex one, pure substance and mixtures, a chemical element and a simple substance; develop skills to distinguish simple substances from complex ones, based on their chemical formulas, teach to highlightthe main thing is to compare, analyze, draw conclusions.
Lesson objectives
educational : 1. to reveal the concepts: simple and complex substances as a form of existence of chemical elements
Educational : 1. To develop cognitive interest in the subject being studied; 2. create conditions for mastering the methods of studying the composition of matter; 3.fto form the ability to search, process, analyze and systematize information; 4. pdevelop the ability to logically express their point of view; 5. teach reflection techniques, develop adequate self-esteem; 6. develop the ability to receive information.
Educational: independently solve problems using existing knowledge; develop the ability to analyze, compare, compare and generalize;learn to be independentin different types of activities; make conclusions.
Planned results.
1. Formation of ideas about the forms of existence of chemical elements in nature and the development of knowledge about chemical elements.
2. Development of students' knowledge about the physical properties of substances.
3. Development of scientific thinking of students in the formation of skills to compare and describe chemical objects in the course of independent performance of exercises and complex tasks, as well as in the development of skills to apply knowledge and methods of action in new conditions.
4. The formation of the scientific worldview of schoolchildren and the assimilation of the leading worldview ideas of the course: the cognizability and unity of the material world, the dependence of the properties of substances on its composition and structure.
5. Development of interest and motivation for studying chemistry when referring tolife experienceschoolchildren and systematization of knowledge about the distribution and relationship of substances in nature.
Basic terms and concepts: simple and complex substances, chemical compounds, chemical element, atoms and molecules, qualitative and quantitative composition
During the classes:
1. Organizational moment
So, friends, pay attention -
After all, the bell rang.
Sit comfortably -
Let's start the lesson soon!
2 . Checking homework.
Traditionally again
We start checking
Exercise 1. Task 4 p. 32
Carbon dioxide is a molecular substance, while sand is non-molecular.
Task2.
In the table, write the letter “X” or “F” (chemical or physical) against each phenomenon, and the letters “T” or “T” against bodies and substances.
"B" respectively.
Task3. Define the terms "molecule" and "atom", "ions", "crystal lattice"
Task 4. Determine the composition: H 2 , O 2 , CO , Cl 2.
3. Learning new material.
In chemistry, in addition to the terms "atom" and "molecule", the concept of "chemical element" is often used. What is common and how do these concepts differ?
A chemical element is an atom of the same kind. So, for example, all hydrogen atoms are the element hydrogen; all oxygen and mercury atoms are the elements oxygen and mercury, respectively.
The names of chemical elements and the simple substances they form almost always coincide, so they must be distinguished by meaning.
For example: 1. Oxygen was collected in a test tube - here oxygen is a simple substance;
2. The composition of the water molecule includes oxygen - here we are talking about a chemical element.
O 2 , Cl 2. H 2 O, CO 2
How are oxygen and chlorine molecules different from water and carbon dioxide molecules?
Students can answer that oxygen and chlorine molecules are formed by atoms of the same type. – Simple substances.
Substances water and carbon dioxide are formed by atoms of different types. - Complex substances.
Simple substances - substances formed by atoms of one chemical element.
Ne, Ar, O 2 , Br 2 , I 2 ,O 3 , P 4 , S 8
(Monatomic simple substances are molecules of inert gases;
diatomic - molecules of hydrogen, oxygen, chlorine, bromine, iodine; triatomic - ozone, tetraatomic - phosphorus, etc.)
The names of simple substances often coincide with the name of the CE, the atoms of which they are formed.
Simple substances are characterized by certain physical properties (state of aggregation, color, density).
Complex substances (chemical compounds) - These are substances formed by atoms of different chemical elements interconnected.
H 2 O, C 6 H 12 O 6 , NaCl, KMnO 4 , CO 2 , CO
(water, glucose, sodium chloride - table salt, potassium permanganate - potassium permanganate, carbon dioxide, carbon monoxide).
Complex substances are characterized by certain physical properties.
SUBSTANCES
simple complex
H 2 ,O 2 , N 2 , Cl 2 H 2 Oh, CO 2 , H 2 SO 4
Working with the scheme 34 p.9
Fixing the topic “Simple and complex substances.
Exercise. Divide the following substances into simple and complex:SO 2 K, Cu, N 2 , O 2 , Cl 2 , LiI, Al 2 O 3 , H 2 , Br 2 , NaCl, MgSO 4 , KOH, Fe, Au, Ag, ZnO, KF, Cr, SO 3
Present the result in the form of a table:
COMPLEX SUBSTANCESK, Cu, N 2 ,O 2 , Cl 2 , H 2 , Br 2 , Fe, Au, Ag, Cr,
SO 2 Al 2 O 3 , NaCl, MgSO 4 , KOH, ZnO, LiI KF, SO 3
Test.
№1
How many simple substances are written in a series of formulas:
N 2 ,O 3 , HNO 3 , P 2 O 5 H 2 O, NaOH., S, Fe, CO 2 ,
№2
Both substances are complex:
A) C (coal) and S (sulfur);
B) Fe (iron) and CH 4 (methane);
AT)CO 2 (carbon dioxide) andH 2 O(water);
№3
Choose the correct statement:
Simple substances are made up of atoms of the same kind.
A) False
B) right
№4
In what case is it about iron as a chemical element?
A) Iron sulfide contains one iron atom.
B) Iron is part of the composition of rust;
C) Iron has a metallic luster;
D) Iron is a metal that is attracted to a magnet;
№5
In what case is it about oxygen as a simple substance?
A) Oxygen is a gas that supports respiration and combustion;
B) Fish breathe oxygen dissolved in water;
C) The oxygen atom is part of the water molecule;
D) Oxygen is present in the air.
Perform practical tasks in the form of independent work.
Instead of dots, insert the necessary expressions (chemical element, simple substance, complex substance, mixture): a) zinc oxide__
Since it consists of _______________________, zinc and oxygen; When ____________________ mercury oxide is heated, two ___________________________ are formed: mercury and oxygen.
Reflection and summing up.
What new did you learn in the lesson?
What questions caused difficulty?
What knowledge have you acquired today?
Homework. §9-10 study. definitions, test tasks p.36. 39
Literature:
1. Textbook Chemistry G.E. Rudzitis, F.G. Feldman. 8th grade.
2.N.P. Troegubova, E.N. Strelnikova KIM Chemistry Grade 8. Moscow "Vako", 2014.
3. O.G. Grigorovich and others. Master class. Chemistry of lesson development Grade 7
Vesta 2008.
4. M. V. Knyazeva. Chemistry lesson plans according to the textbook by G.E. Rudzitis, F.G. Feldman. 8th grade. Volgograd "Teacher" 2013
