Lesson on the topic of simple and complex substances. Chemistry lesson summary "Topic: Simple and complex substances
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 -
consists of unified elements.
S. P. Shchipachev, “Reading Mendeleev.”
In chemistry, except for terms "atom" And "molecule" the concept is often used "element". What do these concepts have in common and how do they differ?
Chemical element – these 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 are known, that is, more than 107 chemical elements. It is necessary to distinguish between the concepts of “chemical element”, “atom” and “simple substance”
Simple and complex substances
According to their 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 differing in properties is called allotropy For example, the element oxygen O has two allotropic forms - dioxygen O 2 and ozone O 3 with different numbers of atoms in the molecules.
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. There are two types of molecules of matter:
1. Simple– the molecules of such substances consist of atoms of the same type. In chemical reactions they cannot decompose to form several simpler substances.
2. Complex– the 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 between concepts "chemical element" And “simple substance” possible by comparing the properties of simple and complex substances. For example, a simple substance - oxygen– a colorless gas necessary for breathing and supporting combustion. The smallest particle of the simple substance oxygen is a molecule that consists of two atoms. Oxygen is also included in carbon monoxide (carbon monoxide) and water. However, water and carbon monoxide contain chemically bound oxygen, which does not have the properties of a simple substance; in particular, it cannot be used for respiration. Fish, for example, do not breathe chemically bound oxygen, which is part of the water molecule, but free oxygen dissolved in it. Therefore, when we talk about the composition of any chemical compounds, it should be understood that these compounds do not contain simple substances, but atoms of a certain type, that is, the corresponding elements.
When complex substances decompose, atoms can be released in a free state and combine to form simple substances. Simple substances consist of atoms of one element. The difference between the concepts of “chemical element” and “simple substance” is also confirmed by the fact that 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 to simple and complex substances:
Simple substances are those that consist of atoms of one chemical element.
Complex substances are those that consist of atoms of different chemical elements.
The difference between the concepts of “mixture” and “chemical compound”
Complex substances are often called chemical compounds.
Try to answer the questions:
1. How do mixtures differ in composition from chemical compounds?
2. Compare the properties of mixtures and chemical compounds?
3. In what ways can you separate the components of a mixture and a chemical compound?
4. Is it possible to judge by external signs the formation of a mixture and a chemical compound?
Comparative characteristics of mixtures and chemicals
|
Questions to match mixtures to chemical compounds |
Comparison |
|
|
Mixtures |
Chemical compounds |
|
|
How do mixtures differ in composition from chemical compounds? |
Substances can be mixed in any ratio, i.e. variable composition of mixtures |
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 other properties are formed |
|
In what ways 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 broken down through 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 the release of heat or other signs of chemical reactions |
The formation of a chemical compound can be judged by the signs of chemical reactions |
Tasks for consolidation
I. Work with simulators
II. Solve the problem
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 consist of atoms of the same type.
A) Correct
B) Incorrect
№4
What is typical for mixtures is that
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 using a chemical reaction.
№5
The following are typical for “chemical compounds”:
A) Variable composition;
B) Substances contained in 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 are we talking about gland how about chemical element?
A) Iron is a metal that is attracted by a magnet;
B) Iron is part of rust;
C) Iron is characterized by a metallic luster;
D) Iron sulfide contains one iron atom.
№7
In what case are we talking 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 part of air.
Subject: Simple and complex substances. Chemical element.
Developed by: Teryukova Elena Alexandrovna
biology and chemistry teacher
With. Arkhangelskoe. Voronezh region
Lesson objectives: study the concepts of “simple and complex substance”, “chemical element”, “allotropy”;
Learn to recognize simple and complex substances, learn to make a comparative description of a “mixture” and a “chemical compound”
- educational: formulate a clear idea of a simple and complex substance, a chemical element, define the concept of “allotropy”;
- developing: develop the ability to extract information from oral communications, video fragments, presentations, and observed processes; describe observations, diagrammatically depict instruments;
develop the ability to analyze data, identify the essence of observed processes, generalize and draw conclusions;
develop the ability to formulate and argue one’s own opinion, develop independence;
continue the formation of students’ chemical speech, creative thinking, rules of scientific communication, and the ability to predict the results of activities;
organize independent activities, improve knowledge self-assessment skills
- raising: cultivate a culture of intellectual work; a sense of responsibility, self-confidence, self-demandingness; ability to work in pairs.
Planned results:
Subject: know clearly what “simple and complex substance”, “chemical element”, “allotropy” are.
Be able to identify the distinctive 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 when conducting simple chemical experiments using laboratory equipment and instruments;
the ability to conduct and describe independently performed chemical experiments using their native language and the language of chemistry;
the ability to draw conclusions and conclusions from observations and studied chemical laws.
Metasubject:
Regulatory UUD
the ability to correlate one’s actions with the planned results, monitor one’s activities in the process of achieving results, determine methods of action within the framework of the proposed conditions and requirements, adjust one’s actions in accordance with the changing situation, evaluate the results of solving assigned tasks, etc.
Cognitive UUD
A clear understanding of “simple and complex substances”, “chemical element”, “allotropy”; apply them in practice.
the ability to create, apply and transform signs and symbols, models and diagrams to solve educational and cognitive problems;
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 field of use of information and communication technologies (ICT competencies);
using various sources to obtain chemical information;
setting and formulating the goals and objectives of the lesson; formulation and argumentation of personal opinion
Communicative UUD
consciously and voluntarily construct a speech utterance in oral form; answer questions in a reasoned manner, justify your 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.
Updating knowledge.
Setting a learning task.
Assimilation of new knowledge and primary consolidation.
Physical education minute.
Consolidation of the studied material.
Homework.
During the classes:
Lesson steps
Developed skills
Teacher activities
Student activities
1. Organizational moment.
Target:
Creating a working mood for students in the lesson, motivating them to study. Determine the level of students’ preparation for the lesson
Personal:
determine common and individual work rules for everyone
Metasubject:
Regulatory UUD
the ability to monitor 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 classroom and office for the lesson. Absent. I inform you that we have a lesson in learning new material.
Preparing to check your homework.
Home check
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.
Greeting from the teacher. Checking the workplace: location of educational supplies, availability of handouts, laboratory equipment.
Prepare for assignments.
Complete tasks individually.
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 maintain discipline in class and treat the teacher and classmates with respect. Formation of thoughts about the need to study the subject of chemistry, about 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 teacher assignments.
Communication UUD: ability to perceive information by ear, answer teacher’s questions
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. All that remained was to understand what these particles were.
Over the next 150 years, after the works of Boyle and Mariotte, the efforts of chemists were aimed at establishing the composition of various substances.
And scientists have succeeded in this. Let's try too.
3. Statement of the educational task.
Target:
Motivate students to learn new knowledge.
Determining 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 construct a speech utterance in oral form; answer questions in a reasoned manner, justify your point of view; listen and understand the speech of others
Regulatory UUD:
accept the educational-cognitive task and maintain it until the end of the educational activities;
correct your own answers and those of your classmates
Cognitive UUD:
setting and formulating the goals and objectives of the lesson; formulation and argumentation of personal opinion;
awareness of the educational-cognitive task
There are a huge number of substances in nature.
We have found out that substances consist of atoms and molecules.
Atoms, under normal conditions, cannot exist alone for a long time. They are capable of combining with the same or other atoms.
What is the result?
How can we explain the wide variety of substances in nature?
What do you think substances can be divided into according to their composition?
A collection of atoms with the same or similar characteristics is.....?
When trying to answer the questions, please try to formulate the purpose and objectives of our lesson.
Conclusion: During today's lesson we will learn what results from the combination of atoms, how substances are divided according to composition, and what a chemical element is. Let's learn about such a phenomenon as “allotropy”.
We will consolidate the acquired knowledge in practice.
Students listen to the teacher and perceive information.
They are trying to answer questions.
Formulate the goals and objectives of the lesson.
They draw conclusions.
4. Studying new material.
Target:
Study the concepts of “simple and complex matter.” “chemical element”, “allotropy”;
Study the distinctive characteristics of a “mixture” and a “chemical compound.”
Personal:
the ability to manage one’s cognitive activity; determine general and individual rules of behavior;
the formation of a responsible attitude towards learning, the readiness and ability of students for self-development and self-education based on motivation for learning and cognition, conscious choice and construction of a further individual educational trajectory;
formation of communicative competence in communication and cooperation with peers and adults in the process of educational, training and research activities
Metasubject:
Regulatory UUD
the ability to correlate one’s actions with the planned results, monitor one’s activities in the process of achieving results, determine methods of action within the framework of the proposed conditions and requirements, adjust one’s actions in accordance with the changing situation, evaluate the results of solving assigned tasks
Cognitive UUD
Give a precise definition of the concepts “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 diagrams to solve educational and cognitive problems;
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 field of use of information and communication technologies (ICT competencies)
Communicative UUD
consciously and voluntarily construct a speech utterance in oral form; answer questions in a reasoned manner, justify your point of view; enter into educational collaboration with the teacher and classmates, carry out joint activities in pairs and groups
Subject:
mastering the conceptual apparatus of the lesson
Teacher's story.
Atoms of different substances are connected to each other in a strictly defined order, the establishment of which is one of the most interesting activities of a chemist.
Scientists of the past, substances that decomposed into simpler ones, were called “compounds (complex substances) - for example, water (remember the previous lesson - electrolysis of water), carbon dioxide, iron scale. Substances that cannot be further decomposed were called “elements” (simple substances), for example: hydrogen, oxygen, copper, gold.
Creating a cluster:
Substances
Simple Complex
Complex substances 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 that differ 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.
About 90 different chemical elements are found in nature. By now, physicists have learned to create new, missing types of atoms. Such atoms (and, accordingly, such chemical elements) are calledartificial.
More than 2 dozen artificially obtained elements have been synthesized to date.
Each element has a Latin name and a one- or two-letter symbol.
Compiling the table:
Creating a cluster:
"Forms of existence of a chemical element."
Chemical element
Free atoms Complex substances
Simple substances
Simple substances - These are substances that consist of atoms of one chemical element.
Complex substances - substances that consist of atoms of various chemical elements.
One of the first chemists to point out the need to distinguish between the concepts of a simple substance and a chemical element was D.I. Mendeleev. In fact, each simple substance is characterized by certain physical and chemical properties. When some simple substance enters into a chemical reaction and forms a new substance, it loses most of its properties. Example: iron, when 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 consisting of the same chemical element.
Example: a piece of phosphorus is a white translucent substance with a melting point of 44.2 O C, very poisonous, phosphorus glows in air and in the dark and can spontaneously ignite.
Phosphorus is a simple substance; it cannot be broken down into other substances.
But, if phosphorus is heated without access to air, it begins to glow in the dark, becomes non-toxic, and does not spontaneously ignite in air, and these new properties do not disappear when heating stops.
At the same time, the substance we took does not decompose, nothing is added to it, but a different form of existence of the same element in a free state is observed:
1st substance – white phosphorus, 2nd substance – red phosphorus.
Like phosphorus, many other elements can exist in a free state 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, carbyne, graphene.
Phosphorus: white, red, black.
Sulfur: rhombic, monoclinic, plastic.
Drawing up a table: “Comparative characteristics of mixtures and chemical elements.”
(Annex 1).
Students listen to the teacher and perceive information.
Write down the definition in your notebook.
Make up a cluster.
Write down definitions.
Fill out the table.
5. Physical education minute.
Exercises for the eyes.
Do the exercises.
6. Fixing the material.
Target: generalization and systematization of acquired knowledge.
Personal UUD:
The ability to manage your cognitive activity.
Regulatory UUD:
The ability to monitor one’s activities in the process of achieving results.
Solving practical tasks.
(Appendix 2).
Grading.
Complete tasks.
Participate in discussions, complement each other, analyze the answers.
Clean the workplace.
7. Homework.
Write down homework.
Satenova Zhanna Alikovna
chemistry teacher
KSU "Kos - Istek secondary school" Aktobe region, Kargaly district, village. Kos – Expired
| Learning objectives achieved through this lesson (Link to curriculum) | 7.1.2.2 - know that each chemical element is designated by a symbol and is a specific type of atom; |
| The purpose of the lesson | For all students, provide conditions for the perception and understanding of the concepts of “chemical elements”, “metals” and “non-metals”, “simple substance” and “complex substance”; For most students, to promote the formation of research skills in determining the physical properties of Me and HeMe; |
| Criteria for evaluation | Knows that a chemical element is represented by a symbol and is a specific type of atom; Explains the belonging of elements to Distinguishes between simple and complex substances |
| Language goals | Students can define the terms: “chemical element”, “simple substance”, “complex substance”. Explain the difference between a metal and a non-metal, a simple and a complex substance. |
| Instilling values | As part of the Patriot Act "Mangilik El» Industrialization and economic growth based on innovation: Chemical production is developing in our country, 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 produced from the substances of our subsoil |
| Intersubject communication | Interdisciplinary communication in the lesson is carried out with the subject of natural science when studying the section classification of substances |
| Prior knowledge | They know the composition of matter (atoms and molecules), the physical properties of metals from the 5th grade Natural Science course |
During the classes
(Formulate the topic of the lesson)
Well done, we have formulated the topic of the lesson.
The epigraph of our lesson today will be the following words:
“On your own, working. You will do everything for your loved ones and for yourself, and if there is no success at work, failure is not a problem, try again.” D.I. Mendeleev
It was not by chance that I took these words. Today you will do a lot on your own, you will gain knowledge yourself. I suggest you formulate lesson goals 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,” the concept “element” is often used. What do these concepts have in common and how do they 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 according to their composition are divided into simple, which contain atoms of only one chemical element, and complex, which contain atoms of different chemical elements.
Let's do the exercises:
(individual work)
Simulator No. 2
Simulator No. 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 strong but flexible character, they were warm in communication and wore shiny clothes. And the inhabitants of the small nation wore different clothes, they were cold and fragile. What are these two peoples?
Feedback: verbally
Division into groups: stickers of different colors with Me and NeMe 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. No. 2
Assignment: “Research method”
To answer these questions, I suggest you do some independent work. You have been given simple substances: sulfur, iron, graphite, aluminum. Study their physical properties and fill out table No. 1 using the instruction cards.
After completing the task, we check that the table is filled out correctly (Feedback) o Through experimentation, you became convinced that the properties of metals differ from the properties of other substances. All metals have a number of common physical properties. Name them?
Thematic warm-up.
F.O. No. 3
Assignment: “Cube Method”
1. Describe
2. Compare
3. Associate
4. Analyze
5. Offer
6. Give reasons
Handout
Slide No. 6,7,8
Table No. 1
Table No. 2
Slide No. 10,11
(4 min)
adherence to technique
security.
The correct answers are on the slide, oral feedback is provided
After solving the riddle, verbal feedback is given.
F.O. No. 2
Let's check the correctness of filling out the table, conduct mutual assessment, exchange work between groups, give an assessment to the group on completing the task.
F.O. No. 3 Individual work
It's called Me children stand up and raise their hands up, NeMe children sit down and clap their hands.
The simple substance is called children clapping, the complex substance is called children stomping.
Topic determination task:
Express your opinion about what these symbols may mean.
The purpose of training 7.1.2.2 - know that each chemical element is designated by a symbol and is a specific type of atom; 7.1.2.4 - classify substances into simple and complex;
Level of thinking 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 based on physical properties.
Level of thinking skills Higher order 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
"Study of the physical properties of simple substances"
Exercise 1. Look at samples of substances and fill in the columns of the table.
- Fill in columns 3 and 4 of the table.
- Twist the aluminum in the light. Shiny? Place “+” or “-” in column 5.
- Bend the sample. Bends? Place “+” or “-” in column 6.
- Place the aluminum in the crook of your elbow. Warm? Put “+” or “-” in column 7.
- 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. Distribute the presented substances into two groups, choosing a key feature. Write down the resulting groups of substances in your notebook, indicating the distribution characteristic(s).
The purpose of training.
7.1.2.2 - know that each chemical element is designated by a symbol and is a specific type of atom;
7.1.2.3 - classify elements into metals and non-metals;
7.1.2.4 - classify substances into simple and complex;
Level of thinking
skills
Higher order skills
Evaluation criterionstudent
Assignment: “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 for on each side of which is written
- Describe
- Compare
- Associate
- Analyze
- Suggest
- Give reasons
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 and complex matter.
Lesson 7. Topic: “Simple and complex substances. Relative atomic and molecular masses"
Goal: to develop in students the concept of “relative atomic mass”, relative
molecular mass"
Objectives: - study the concepts: simple and complex substances, relative molecular weight; - learn to calculate relative molecular weight; identify simple and complex substances using formulas;
Solve problems independently using existing knowledge;
Develop the ability to analyze, compare, contrast and generalize;
Equipment: PTCE
During the classes:
1. Introductory and motivational stage
a) organizational moment
b) psychological attitude
2. Updating previous knowledge
Chemical warm-up.
The teacher shows cards with symbols of chemical elements, students name them.
TEST – checking previously studied material (to check answers, desk neighbors exchange pieces of paper and give marks – mutual checking)
Task 1: match .
1. Argentum 4. Silicium 7. Arsenicum 10. Ferrum
2.Aurum 5.Stannum 8.Stibium
3. Hydrargyrum 6. Plumbum 9. Cuprum
a)Ag; b)Cu; c)Fe; d)Sb; e)Sn; e)Hg; g)Pb; h)As; i)Si ; j)Au .
3. Learning new material
Relative atomic mass (Ar) of an element is the ratio of the mass of an atom of a given element to 1/12 of the mass of a carbon atom; it is a dimensionless quantity.
For example: Ar(H 2) = 1 · 2 = 2
Ar(Cl 2) = 35.5 · 2 = 71
Relative molecular weight (Mr) of a substance is the sum of the relative atomic masses of the elements that form the substance.
To the grouping of complex ones.
The guys make a diagram in their notebooks (with the help of the teacher):
SUBSTANCES
simple complex
H 2 , O 2 , N 2 ,Cl 2 H 2 O, CO 2 ,H 2 SO 4 O
practicing concepts – simple and complex substances
Relative molecular weight and its calculation (with independent work)
Molecular weight
The concept is relative.
Its meaning is physical
Not surprising at all.
Mass so that the molecules
quickly compare
Needed for a twelfth
carbon split.
Students rewrite the formula:
m (in-va)
Mr (v-va)= ------------------
1/12 m (C)
You are molecular
Calculate the mass:
Atomic masses
Put it all together
And by the number of atoms
At the same time, multiply.
The teacher shows students how to correctly calculate the relative molecular mass of a substance: sodium oxide and sulfuric acid.
4 . Consolidation
Task 1. 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 table form:
| SIMPLE SUBSTANCES | COMPLEX SUBSTANCES |
Calculate the molecular masses of substances (check yourself).
5. Homework
6. Reflective-evaluative stage
Summary of a chemistry lesson in 8th grade on the topic: Simple and complex substances. The lesson is accompanied by a presentation. Purpose of the lesson: familiarization with simple and complex substances - the main forms of existence of elements in nature; completing tasks to master the concepts of “simple substance”, “complex substance”, develop the ability to distinguish simple substances from complex ones, based on their chemical formulas.
Download:
Preview:
Educational Management Department
Svobodnensky district, Amur region
Municipal educational institution Rogachevskaya secondary school
Subject:
"Simple and complex substances"
Chemistry 8th grade
With. Rogachevka
Target: familiarization with simple and complex substances - the main forms of existence of elements in nature; completing tasks to master the concepts of “simple substance”, “complex substance”,Develop the ability to distinguish simple substances from complex ones based on their chemical formulas.
Lesson Objectives
Educational: 1. reveal the concepts: simple and complex substances as a form of existence of chemical elements
Developmental: 1.Develop cognitive interest in the subject being studied; 2. create conditions for mastering techniques for studying the composition of matter; 3.develop 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, contrast 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 development of knowledge about chemical elements.
2. Development of students' knowledge about the physical properties of substances.
3. Development of students’ scientific thinking in developing the ability to compare and describe chemical objects during independent performance of exercises and complex tasks, as well as in developing the ability to apply knowledge and methods of action in new conditions.
4. Formation of the scientific worldview of schoolchildren and the assimilation of the leading ideological ideas of the course: the knowability 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 by referring to the life experience of schoolchildren and systematizing knowledge about the distribution and interconnection of substances in nature.
During the classes:
1. Organizational moment
Hello! Hello, dear guests!
Why are you so sad in chemistry class?
Tell me quickly: in what lesson,
Who dared to offend you in the recent past?
So I’ll cheer you up today,
I know the best way:
Let's study the topic!
2 . Checking homework.
According to tradition again
Let's start as usual
We are checking our homework.
This is familiar to us.
Get ready to answer
I'll call you now!
Are you scared? Just kidding...
I won't call!
I’d rather give you the tests,
I’ll give everyone ratings later.
Exercise 1. In the table, write the letter “X” or “F” (chemical or physical) against each phenomenon, and write the letters “T” or “T” against bodies and substances.
"B" accordingly.
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 silver items. | ||
Rotting of plants. | ||
Melting iron. | ||
Glass. | ||
Iron. | ||
Bucket. | ||
Hare. |
Task2. Define the concepts “molecule” and “atom”.
Task 3. Determine the composition: H 2 O, O 2, CO 2, Cl 2.
3. Studying new material.
In chemistry, in addition to the terms “atom” and “molecule,” the concept “element” is often used. What do these concepts have in common and how do they differ?
A chemical element is 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.
O 2, Cl 2. H 2 O, CO 2
How do oxygen and chlorine molecules differ from water and carbon dioxide molecules?
Students may answer that oxygen and chlorine molecules are formed by the same type of atom. - Simple substances.
The substances water and carbon dioxide are formed by different types of atoms. - 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
(Monoatomic simple substances - 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 chemical elements whose atoms they are formed from.
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 connected to each other.
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
H2, O2, N2, Cl2H2O, CO2, H2SO4
Pin a topic“Simple and complex substances. Relative molecular mass 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 table form:
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 masses of substances (check yourself).
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 consist of atoms of the same type.
A) Correct
B) Incorrect
№4
In what case are we talking about iron as a chemical element?
A) Iron is a metal that is attracted by a magnet;
B) Iron is part of rust;
C) Iron is characterized by a metallic luster;
D) Iron sulfide contains one iron atom.
№5
In what case are we talking 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 part of 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 practical tasks:
- 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) composition of chemical compounds ___________________ structure _______________________________.
P/n Phenomena. Bodies and substances X, F; 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 silver items. X 7. Rotting of plants. X 8. Melting iron. F 9. Glass. B 10. Iron. B 11. Bucket. T 12. Hare. T
Task2. Define the concepts “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 type of atom. Complex substances are made up of different types of atoms. How to express the composition of a substance using the symbols 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, SO3
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
