lesson project
Lesson project for learning new material on the topic "Simple and Complex Substances" (lesson number 2)Grade 8
WMC“Chemistry grade 8. Gabrielyan O.S. 2014"
Class composition: there are 28 people in the class, 27 of them with a developmental norm, 1 with a mental retardation (1 type)
Lesson Objectives: CREATE CONDITIONS FOR
"ordinary" children
"special" children
Discovery of a way to find differences between a simple substance and a complex one, a pure substance and a mixture, a chemical element and a simple substance;
formation of the ability to distinguish simple substances from complex ones, based on their chemical formulas
developing the ability to identifythe main thing is to compare, analyze, draw conclusions.
To develop the ability to provide assistance in the position of a "little teacher"
Acceptance and understandingwayaction forfinding differences between a simple substance and a complex one, a pure substance and a mixture, a chemical element and a simple substance, based on their chemical formulas
To develop the ability to negotiate when working in pairs
PLANNED RESULTS
Personal
:
showing interest in the problem
Metasubject
P
TO
Interact in pairs
R
- ability to work on the development of an algorithmfinding differences between a simple substance and a complex one, a pure substance and a mixture, a chemical element and a simple substance
subject
Personal : showing interest in the problem
Metasubject
P
Use sign-symbolic models
TO
Interact in pairs
R
Plan actions in accordance with the set educational task;
- algorithmic skills finding difference between a simple substance and a complex
Exercise self-control and self-assessment.
subject : identify simple substances and complex, pure substances and mixtures, chemical elements and simple substances
Lesson content
Lesson structureInteraction in the educational process
Note
Actions of the teacher
Student actions
with the norm of development
Student actions
with disabilities
Motivation
Are you all ready for the lesson to learn about something new?
Refers to the class:
Look at the formulas of the substances written on the board.
– What do they mean?
How are they similar, how are they different?
Yes that's right!
In the first column, substances consisting of atoms of the same type, and in the second - from atoms of different types
In the first column of matter, easier written, few atoms
I organize a situation of control and self-assessment of readiness for the upcoming work in the lesson.
Simple and complex substances are written on the board in two columns.
H2H2O
O 2 K 2 O
N 2 NH 3
S H 2 SO 4
2. goal setting
Try to formulate the topic of the lesson.
The theme of the lesson will be:
"Simple and Complex Substances"
- Who can repeat the purpose of the lesson?
Talk to each other in pairs, and the "little teachers" will check you
Working in pairs, complete the sentence “Today I will study at the lesson ....”
Formulate the topic of the lesson
Recorded in a notebook
"Little teachers" check the correct pronunciation of the topic
Work in pairs to determine the purpose of the lesson.
Repeat the theme of the lesson
Recorded in a notebook
They speak to each other.
Work in pairs, pronounce the goal
- “Today I will study at the lesson identify simple and complex substances
I ask the "special child" in the class, I praise.
An opportunity is given to respond to a “special” child.
Fixing the topic on the board.
3. Planning
To easily learn to distinguish between simple and complex substances, we need a plan that includes questions:
-What?
-How?
-I apply
- Scale of success.
Refers to a group of "special children":
You have cut strips on the tables with certain items that need to be distributed in the desired sequence
Work in pairs to create a plan that includes the following questions:
-What?
-How?
-I apply
- Scale of success.
Arrange plan items in order
Fixing the plan on the board:
4. Implementation of the learning task
-What do we do at step 1 of the plan?
Whatcan you tell me about simple substances
Whatcan you tell me about complex substances
How to distinguish between simple and complex substances?
From the row written on the board, choose only simple substances. Check if your neighbor did the right thing in a pair.
How many complex substances are in this series? Write down a substance consisting of 4 atoms, of which 3 belong to the same species.
Refers to a group of "special children":
Look carefully at the formulas of complex substances, count how many atoms of different types are in each molecule
Write a formula for a substance that has two iron atoms and three oxygen atoms. What is this substance?
Test each other in pairs
They tell what they learned about simple substances, give an example. Formulate and write down the definition
Tell what they learned about complex substances, give an example
Formulate and write down the definition
Compose and write an algorithm
Issued, checked
Answer:
3 complex substances
MgO , PH 3 , HNO 3
Discharge PH 3
Compose, check, determine the type of substance.
Checking
Write down the definition and example
Write down the algorithm
Issued, checked
Answer:
3 complex substances
They count the number of atoms of different types in each molecule, find a molecule with four atoms, determine that 3 of them belong to the same species.
Discharge PH 3
Write down the signs of chemical elements, put the number of atoms. They try to determine the type of substance using hint cards.
Checking
The “special” child is given the opportunity to repeat what he wrote in his notebook, which he gave an example.
There are a number of substances on the board:
F 2 , Cu, MgO, PH 3 , HNO 3 , C
Highlight complex substances on the board
We check verbally
Separately check in special children, fixing whether there are difficulties
Topic: "Simple and complex substances"
The purpose of the lesson: explain the difference between a simple substance and a complex one, a pure substance and a mixture, a chemical element and a simple substance; to develop the ability to distinguish simple substances from complex ones, based on their chemical formulas, to teach them to highlight the main thing, 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. to form the ability to search, process, analyze and systematize information; 4. develop the ability to logically express your 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 show independence in various 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. The development of students' scientific thinking in the formation of the ability to compare and describe chemical objects in the course of independent 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.
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.
| Phenomena. Bodies and substances | ||
| Water decomposition | ||
| Evaporation of water from a puddle | ||
| Burning gasoline in a car engine. | ||
| Water distillation. | ||
| Melting iron. | ||
| Pencil. |
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:
| SIMPLE SUBSTANCES | COMPLEX SUBSTANCES |
| K, 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 |
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,
Both substances are complex:
A) C (coal) and S (sulfur);
B) Fe (iron) and CH 4 (methane);
C) CO 2 (carbon dioxide) and H 2 O (water);
Choose the correct statement:
Simple substances are made up of atoms of the same kind.
A) False
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;
In which 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.
Practical task:
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
Satenova Zhanna Alikovna
chemistry teacher
KSU "Kos - Istek secondary school" Aktobe region, Kargaly district, with. Kos - Istek
| Learning objectives achieved on this lesson (Link to curriculum) | 7.1.2.2-know that each chemical element is denoted by a symbol and is a certain type of atom; |
| The purpose of the lesson | For all students, to provide conditions for the perception and comprehension of the concepts of "chemical elements", "metals" and "non-metals", "simple substance" and "complex substance"; For the majority of students, to promote the formation of research skills in determining the physical properties of Me and NeMe; |
| Criteria for evaluation | Knows that a chemical element is denoted by a symbol and is a certain kind of atom; Explains the belonging of elements to Distinguish between simple and complex substances |
| Language goals | Students can define the terms: "chemical element", "simple substance", "complex substance". Explain the difference between metal and non-metal, simple and complex matter. |
| Instilling values | As part of the patriotic act "Mangilik El» Industrialization and economic growth based on innovation: In our country, chemical production is developing, which aims to produce affordable, high-quality items based on simple and complex substances. Independence of Kazakhstan and Astana: Astana is a city under construction, which requires various building materials made from the substances of our bowels |
| Interdisciplinary communication | Interdisciplinary communication in the lesson is carried out with the subject of natural science when studying the section on the classification of substances |
| Prior Knowledge | They know the composition of matter (atoms and molecules), the physical properties of metals from the course "Natural Science" grade 5 |
During the classes
(Formulate the topic of the lesson)
Well done, here we have formulated the topic of the lesson.
The epigraph of our today's lesson will be the following words:
“Themselves, working. You will do everything for your loved ones and for yourself, and if there is no success with work, failure is not a problem, try again ”D.I. Mendeleev
I did not take these words by chance. Today you will do a lot on your own, you will gain knowledge yourself. I suggest that you form the objectives of the lesson based on the topic. (Formulate the purpose of the lesson based on the topic)
(23 min)
(2 minutes)
(8 min)
In chemistry, in addition to the terms "atom" and "molecule", such a concept as "element" is often used. What is common and how do these concepts differ?
Chemical element are atoms of the same type. For example, all carbon atoms are the chemical element carbon, all iron atoms are the chemical element iron.
All elements were structured and classified into the periodic system by the Russian chemist Dmitry Ivanovich Mendeleev in 1869.
All substances are divided into simple, containing atoms of only one chemical element, and complex, which include atoms of different chemical elements.
Let's do the exercises:
(individual work)
Trainer №2
Trainer №3
Now I ask you to listen and guess the riddle. Two peoples lived in one amazing and mysterious country. The inhabitants of a large nation had a firm but plastic character, they were warm in communication and wore shiny clothes. And the inhabitants of a small nation wore different clothes, were cold and fragile. What are these two peoples?
Feedback: verbally
Division into groups: stickers of different colors on which Me and NeMe are written on the back.
The great Russian scientist M.V. Lomonosov defined metal as “a solid, opaque, light body that can be melted on fire and cold forged”.
These properties apply to metals. What other physical properties are characteristic of metals?
What can we say about non-metals?
(The guys collectively discuss the problem and determine the general properties of metals)
F.O. #2
Task: "Research method"
To answer these questions, I suggest you do your own work. You have been given simple substances: sulfur, iron, graphite, aluminum. Study their physical properties and complete Table 1 using the instruction cards.
After completing the task, check the correctness of filling the table (feedback) oh by trial and error you were convinced that the properties of metals differ from the properties of other substances. All metals share a number of common physical properties. Name them?
Thematic workout.
F.O. No. 3
Task: "The Cube Method"
1. Describe
2. Compare
3. Associate
4. Analyze
5. Suggest
6. Argue
Handout
Slide №6,7,8
Table No. 1
Table number 2
Slide №10,11
(4 min)
technical compliance
security.
The correct answers are on the slide, oral feedback is given
After guessing the riddle, oral feedback is given.
F.O. #2
Let's check the correctness of filling in the table, conduct mutual evaluation, exchange work between groups, rate the group on the task.
F.O. №3 Individual work
It is called Me children stand up raise their hands up, NeMe children sit down and clap their hands.
The simple substance is called children clap, the complex substance is called children stomp.
Topic assignment:
Give your opinion on what these symbols might mean.
The purpose of training 7.1.2.2-know that each chemical element is denoted by a symbol and is a certain type of atom; 7.1.2.4 - classify substances into simple and complex;
The level of mental skills knowledge and understanding
Evaluation criterionstudent
Descriptor:
Knows chemical symbols and their names.
- indicates simple and complex substances
The purpose of training 7.1.2.3 Distinguish between metals and non-metals by physical properties.
The level of mental skills High Tier Skills
Evaluation criterionstudent
Explains the belonging of elements to
metals and non-metals in terms of their
physical properties.
Descriptor:
explains the physical properties of aluminum and
iron is classified as a metal;
- explains by what physical properties, despite
their similarities and differences, sulfur and graphite are classified as non-metals.
Table 1. "Physical properties of simple substances"
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| №
sample |
Substance | State of aggregation | Color | Shine | Plastic | Thermal conductivity | Electrical conductivity |
| 1 | Iron | ||||||
| 2 | Sulfur | ||||||
| 3 | Aluminum | ||||||
| 4 | Graphite |
instruction card
"Investigation of the physical properties of simple substances"
Exercise 1. Consider the samples of substances and fill in the columns of the table.
- Fill in column 3 and 4 of the table.
- Spin the aluminum in the light. Shines? Put in column 5 "+" or "-".
- Bend the sample. Does it bend? Put in column 6 "+" or "-".
- Put the aluminum in the crook of your elbow. Warm? Put in column 7 "+" or "-".
- Do the same with other samples. Fill in the appropriate columns of the table.
- Mark the samples that conduct electric current, based on knowledge from the physics course.
Task 2. Divide the presented substances into two groups, choosing a key feature. Write down the resulting groups of substances in a notebook, indicating the sign (s) of distribution.
The purpose of training.
7.1.2.2-know that each chemical element is denoted by a symbol and is a certain type of atom;
7.1.2.3 - classify elements into metals and non-metals;
7.1.2.4 - classify substances into simple and complex;
The level of mental
skills
High Tier Skills
Evaluation criterionstudent
Task: "The Cube Method"
A table with pictures is given (6 pictures: dishes (Al), oxygen cylinder (O 2), water (H 2 O), copper coil (Cu), nitrogen cylinder (N), fire extinguisher (CO 2)), and a cube on each side of which is written
- Describe
- Compare
- Associate
- Analyze
- Suggest
- Argument
Descriptor:
— are able to describe and compare metals and non-metals, simple matter and complex matter.
— are able to analyze knowledge about Me, NeMe, simple, complex matter.
Synopsis of a lesson in chemistry in grade 8 on the topic: Simple and complex substances. The lesson is accompanied by a presentation. The purpose of the lesson: 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 the ability to distinguish simple substances from complex ones, based on their chemical formulas.
Download:
Preview:
Department of Education Management
Svobodnensky district of the Amur region
MOU Rogachevskaya OOSh
Subject:
"Simple and Complex Substances"
Chemistry Grade 8
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. To develop cognitive interest in the subject being studied; 2. create conditions for mastering the methods of studying the composition of matter; 3. to form the ability to search, process, analyze and systematize information; 4. develop the ability to logically express your 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. The development of students' scientific thinking in the formation of the ability to compare and describe chemical objects in the course of independent 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:
1. Organizational moment
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 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 give you tests
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 | Phenomena. Bodies and substances | X, F; T, V |
Formation of rust on iron objects. | ||
Weathering of rocks. | ||
Evaporation of water from a reservoir. | ||
Boiling water in a kettle. | ||
Burning gasoline in a car engine. | ||
Darkening of silverware. | ||
Rotting plants. | ||
Melting iron. | ||
Glass. | ||
Iron. | ||
Bucket. | ||
Hare. |
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).
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 O, 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 | COMPLEX SUBSTANCES |
K, 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 |
Calculate the molecular weights of 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 which 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 _______________________________.
P / n Phenomena. Bodies and substances Х, Ф; T, B 1. Formation of rust on iron objects. X 2. Weathering of rocks. F 3. Evaporation of water from a reservoir. F 4. Boiling water in a kettle. F 5. Combustion of gasoline in a car engine. X 6. Darkening of silverware. X 7. Rotting plants. X 8. Melting of iron. F 9. Glass. B 10. Iron. B 11. Bucket. T 12. Hare. T
Task2. Define the terms "molecule" and "atom".
Task 3. Determine the composition: H 2 O, O 2, CO 2, Cl 2.
Chemical elements exist in the form of chemical compounds. chemical compounds simple complex substances substances
Simple substances are made up of one kind of atoms Compound things are made up of different kinds of atoms. How to express the composition of a substance using the signs of chemical elements? O 2 H 2 H 2 O index
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
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
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, apart from terms "atom" And "molecule" concept is often used "element". What is common and how do these concepts differ?
Chemical element – they are 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
According to the elemental composition, they are distinguished simple substances, consisting of atoms of one element (H 2, O 2, Cl 2, P 4, Na, Cu, Au), and complex substances, consisting 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, 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 O 2 and ozone O 3 with a different number of atoms in 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.
chemical compounds, for example, mercury (II) oxide HgO (obtained by combining atoms of simple substances - mercury Hg and oxygen O 2), sodium bromide (obtained by combining atoms of simple substances - sodium Na and bromine Br 2).
So let's summarize the above. Molecules of matter are of two types:
1. Simple 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- Molecules of such substances consist of atoms of different types. In chemical reactions, they can decompose to form simpler substances.
The difference between the concepts of "chemical element" and "simple substance"
Distinguish concepts "chemical element" And "simple substance" when 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 the composition of 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. Therefore, when it comes to 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"
Compounds 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?
4. Is it possible to judge by external signs the formation of a mixture and a chemical compound?
Comparative characteristics of mixtures and chemical
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 by external signs 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
Tasks for fixing
I. Work with the machines
II. Solve the task
From the proposed list of substances, write out 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 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);
D) H 2 SO 4 (sulfuric acid) and H 2 (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 by physical properties;
D) Substances in "mixtures" can be separated by a chemical reaction.№5
For "chemical compounds" the following is characteristic:
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 gland how about 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 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.
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