Presentation of crystalline and amorphous solids in materials science. Crystalline and amorphous bodies - presentation. Wet thermometer readings, °C

Crystalline

and amorphous

Prepared by: teacher of mathematics and physics of OGBOU SPO "Tulun Agrarian College" Guznyakov Alexander Vasilievich

Lesson objectives:

educational-

form the concepts: “crystalline body”, “crystal lattice”, “monocrystal”, “polycrystal”, “amorphous body”;
identify the basic properties of crystalline and amorphous bodies;

developing-

develop the ability to highlight the main thing;
develop the ability to systematize material;
develop cognitive interest in the subject using various forms of work;

educational -

cultivate a scientific worldview.

The barely transparent ice, dimming over the lake, covered the motionless streams with crystal.

A.S. Pushkin.

And the crazy chill of emerald, And the warmth of golden topaz, And the wisdom of simple calcite - Only they will never deceive. In them, in the silent fragments of the universe, Sparks of eternal harmonies sparkle. The arrogant image of everyday life fades and melts in these sparks. They give peace and protection, They give the fire of inspiration, entwined in a single chain, with our frailty - links in eternity.

Victor Sletov

emerald crystals

Practical work

Indications dry thermometer, °С	Reading difference dry and wet thermometers, °C	Wet thermometer readings, °C

Define

humidity

Entrance test

1. Name the three states of matter of matter.

- gaseous, liquid, solid.

2. Complete the sentence.

“The state of aggregation of a substance is determined by the location, nature of movement and interaction...”

- molecules.

Entrance test

3. Find the correspondence between the state of aggregation of a substance and the distance between molecules.

- 1b; 2a; 3c.

4. Name the properties of solids.

- retain volume and shape.

1) gaseous;

2) hard;

3) liquid.

a) located in an orderly manner, close to each other;

b) the distance is many times greater than the size of the molecules;

c) located randomly next to each other.

Entrance test

5. Fill in the missing words.

“The transition of a substance from a liquid to a solid state is called ... or ... "

- hardening, crystallization.

Most of the solids around us are substances in a crystalline state. These include building and structural materials: various grades of steel, all kinds of metal alloys, minerals, etc. A special field of physics is solid state physics - deals with the study of the structure and properties of solids. This area of physics is leading in all physical research. It forms the foundation of modern technology.

Solid state physics

Properties of Solids

Doesn't change

What is the reason?

Properties of crystalline solids

Melting point is constant

Have a crystal lattice

Each substance has its own melting point.

Anisotropic (mechanical strength, optical, electrical, thermal properties)

Types of crystals

Amorphous substances

(different Greek ἀ “non-” and μορφή “type, form”) do not have a crystalline structure and, unlike crystals, do not split to form crystalline faces; as a rule, they are isotropic, that is, they do not exhibit different properties in different directions, do not have a certain melting point.

Properties of amorphous bodies

Do not have a constant melting point

They do not have a crystalline structure

Isotropic

Have fluidity

Capable of transitioning into crystalline and liquid states.

Have only “short-range order” in the arrangement of particles

Minerals

Variety of crystals

Amorphous bodies

Look to the root

Types of crystals

Cubic system

Tetragonal

Hexagonal

Rhombohedral

Rhombic

Monoclinic

Triclinic

Liquid crystals

substances that simultaneously have

properties like liquids (fluidity),

and crystals (anisotropy).

Application of liquid crystals

Pressure meters and ultrasound detectors have been created based on liquid crystals. But the most promising area of application of liquid crystalline substances is information technology. Only a few years have passed from the first indicators, familiar to everyone from digital watches, to color televisions with LCD screens the size of a postcard. Such TVs provide very high quality images, consuming a negligible amount of energy from a small battery or battery.

Diamond cutting

The diamond is recognized as the most beautiful and frequently used form of brilliant cut, created for the optimal combination of brilliance and the “play” of light, revealing the jewelry properties of the diamond.

Diamond "Shah"

Diamond "Orlov"

Problem solving

1. A ball machined from a single crystal, when heated, can change not only its volume, but also its shape. Why?

Answer :

Due to anisotropy, crystals expand unevenly when heated.

Problem solving

2. What is the origin of the patterns on the surface of galvanized iron?

Answer :

The patterns appear due to the crystallization of zinc.

Output test

1. Complete the sentence.

“The dependence of physical properties on the direction inside the crystal is called...”

- anisotropy.

2. Fill in the missing words.

"Solid bodies are divided into ... and ..."

- crystalline and amorphous.

3. Find the correspondence between solids and crystals.

- 1a; 2b.

4. Find a correspondence between the substance and its state.

- 1b; 2c; 3b; 4a.

Output test

5. Find a correspondence between the bodies and the melting point.

- 1b; 2a.

You can find out more: http://ru.wikipedia.org/wiki; http://physics.ru/courses/op25part1/content/chapter3/section/paragraph6/theory.html; http://www.alhimik.ru/stroenie/gl_17.html; http://bse.sci-lib.com/article109296.html; http://fizika2010.ucoz.ru/socnav/prep/phis001/kris.html.

Crystalline

Presentation on the topic:

"Amphora substances and crystal lattices"

The work was completed by 8B grade student Arina Leonova

Based on their physical properties and molecular structure, solids are divided into two classes - amorphous And crystalline .

Amphora body

Characteristic feature amorphous bodies is theirs isotropy , i.e., independence of all physical properties from the direction of external influence. Molecules and atoms in isotropic solids are arranged randomly, forming only small local groups containing several particles. In their structure, amorphous bodies are very close to liquids. Examples of amorphous bodies include glass, various hardened resins (amber), plastics, etc. If an amorphous body is heated, it gradually softens, and the transition to a liquid state takes a significant temperature range.

IN crystalline In bodies, particles are arranged in a strict order, forming repeating structures throughout the entire volume of the body. To visually represent such structures, spatial crystal lattices , at the nodes of which the centers of atoms or molecules of a given substance are located. Most often, a crystal lattice is built from atomic ions that are part of the molecule of a given substance.

Crystal

Types of crystalline bodies

solids whose particles form a single crystal lattice.

an aggregate of small crystals of any substance, sometimes called crystallites or crystal grains because of their irregular shape.

Crystalline and amorphous bodies Completed by: Elena Anatolyevna Gotmanova, physics teacher at Municipal Educational Institution “Secondary School No. 15”, r.p. Pervomaisky Shchekinsky district 01/14/2008 ABSTRACT The presentation can be used partially in physics lessons in the 8th grade and in its entirety in the 10th grade; at extracurricular events (physics weeks, seminars, lessons with interdisciplinary connections) Completed in Microsoft PowerPoint Amount of work - , number of slides - 16 Goals and objectives To familiarize students with the structure and properties of solids; Show the role of solid state physics in the creation of materials with predetermined properties; Show the formula of crystals, the symmetry of spatial crystal lattices; Show the practical significance of solids Methodological recommendations for the teacher This presentation can be used in the 10th grade with both two and three hours allocated to the topic “Solids”; To implement differentiated learning, solving high-quality problems can be offered both to the whole class and partially to students with different levels of knowledge; In grade 8, presentation materials related to the study of crystalline solids can be used. Methodological recommendations for students This presentation supports interest in the study of physics; By using this presentation, you expand your horizons, develop abstract thinking; This presentation allows you to consolidate self-education skills. Features of the internal molecular structure of solids. Their properties Crystal is a stable, ordered formation of particles in the solid state. Crystals are distinguished by spatial periodicity of all properties. The main properties of crystals: retains shape and volume in the absence of external influences, has strength, a certain melting point and anisotropy (the difference in the physical properties of the crystal from the chosen direction). Observation of the crystal structure of some substances salt quartz mica diamond Single crystals and polycrystals Metals have a crystalline structure. Typically, a metal consists of a huge number of small crystals fused together. A solid consisting of a large number of small crystals is called polycrystalline. Single crystals are called single crystals. Most crystalline solids are polycrystals, as they consist of many intergrown crystals. Single crystals - single crystals have a regular geometric shape and their properties are different depending on the direction Historical background 1867 Russian engineer A. V. Gadolin was the first to prove that crystals can have 32 types of symmetry. The famous Russian crystallographer E.S. Fedorov proved that there can only be 230 ways to construct a crystal Scientists have found that the correct shape of a crystal is due to the close, ordered arrangement of particles in the crystal Demonstration of various models of crystal lattices diamond graphite salt Note the same distance between salt particles in certain directions Models of graphite and diamond crystal lattices are an example of polymorphism, when the same substance can have different types of packaging Demonstration of evidence of the properties of amorphous bodies 1. Amorphous bodies do not have a specific melting point paraffin glass 2. Amorphous bodies are isotropic, for example: paraffin plasticine The strength of these bodies does not depend on the choice of test direction Demonstration of evidence of the properties of amorphous bodies 3. With short-term exposure they exhibit elastic properties. For example: rubber balloon 4. With prolonged external influence, amorphous bodies flow. For example: paraffin in a candle. 5. Over time, they become cloudy (ex: glass) and devitrify (ex: candy candy), which is associated with the appearance of small crystals, the optical properties of which differ from the properties of amorphous bodies. Solution of qualitative problems A ball made of a single crystal when heated can change not only its volume, but also its shape. Why? A glass cube and a quartz monocrystal cube dipped in hot water. Do the cubes retain their shape? Why don’t spherical crystals exist in nature? Why does snow squeak underfoot in cold weather? Why are there no melting points for glass in the tables of melting points of various substances? Results Students became familiar with the structure and properties of solids; We became familiar with the role of solid state physics in the creation of materials with predetermined properties; Students saw the formula of crystals, the symmetry of spatial crystal lattices; We looked at the practical significance of solids. References 1. 2. 3. O.F. Kabardin Physics. Reference materials. Kabardin O.F. - M. “Enlightenment”, 1988, 367 p. G.Ya. Myakishev, B.B. Bukhovtsev, N.N. Sotsky – Physics. Textbook for 10th grade of general education institutions. Myakishev G.Ya., Bukhovtsev B.B., Sotsky N.N. - Literature, “Enlightenment”, 2007, 366 p. I.G. Vlasova, A.A. Vitebskaya Solving problems in physics. School Student's Handbook. – Vlasova I.G., Vitebskaya A.A., Philological Society “Slovo”, AST, Klyuch-S, Center for the Humanities at the Faculty of Journalism of Moscow State University. M.V. Lomonosov, -M., 1997, 638 p. Answers to qualitative problems A monocrystal is a single crystal whose physical properties depend on the direction inside the crystal, that is, it has anisotropy. Therefore, a ball made of a single crystal, when heated, can expand in different directions unequally, therefore, it can change not only its volume, but also its shape. Glass is an amorphous solid and is isotropic. Single crystals are anisotropic. Consequently, due to the anisotropy of thermal expansion (thermal expansion is not the same in different directions), the quartz cube will take the shape of a parallelepiped. A glass cube will not change its shape. All single crystals are anisotropic, that is, physical properties depend on the direction within the crystals. Consequently, crystal growth is not the same in different directions, and therefore a spherical crystal cannot be grown. Snow consists of a huge number of crystalline snowflakes. In cold weather, the snow creaks under your feet because hundreds of thousands of crystals break on the floor under the force of your feet. This is due to the fact that glass is an amorphous substance that does not have a specific melting point.

Physics lesson notes for grade 10

on the topic “Crystalline and amorphous bodies”

Lesson type : learning new material.

The purpose of the lesson: Reveal the basic properties of crystalline and amorphous bodies. Show the use of crystals in technology.

Tasks

Educational :

to form in students the concepts of crystal, amorphous body, single crystal, polycrystal, to study the properties of crystals and amorphous bodies.

Developmental :

developcognitive interest in the subject, observation,the ability to analyze and draw conclusions from observed phenomena, the ability to generalize the results obtained, the skills of independent work with information

Educational :

formation of a scientific worldview, cultivate a feelingindependence, organization, responsibility.

Teacher equipment: projector, computer, interactive whiteboard, presentation “Crystalline and amorphous bodies”, models of crystal lattices, crystals grown by students in preparation for the lesson, a vessel with hot water, video fragment “Educational information about crystals”

Equipment for students: collections of minerals, a lens, a set for studying substances (a test tube with a crystalline substance, a test tube with an amorphous substance, a bag of sodium salt, an empty test tube, a thermometer, a stopwatch), netbooks.

Lesson Plan

Organizing time.

Setting a goal.

Learning new material.

Primary consolidation

Reflection

Homework

During the classes

Organizing time.

Setting a goal.

“The time for miracles has come, and we have to look for the reasons for everything that happens in the world,” wrote William Shakespeare. In the world around us, various physical and chemical processes occur with substances. And, despite the diversity of substances, they can only exist in three states of aggregation. Today in the lesson you will get acquainted with crystalline and amorphous bodies and their properties.

Dividing the class into groups.

Learning new material.

“...The growth of a crystal is like a miracle,
When ordinary water
After a moment's hesitation, she became
A sparkling shard of ice.
A ray of light, lost in the edges,

Will crumble into all colors...

And then it will become clearer to us,
What beauty can be..."

Leontyev Pavel

Since ancient times, crystals have attracted people with their beauty. Their color, shine and shape touched the human sense of beauty, and people decorated themselves and their homes with them. For a long time, superstitions have been associated with crystals; like amulets, they were supposed to not only protect their owners from evil spirits, but also endow them with supernatural abilities. Crystal jewelry is as popular now as it ever was. When these same minerals began to be cut and polished like precious stones, many superstitions were preserved in “lucky” talismans and “own stones” corresponding to the month of birth.

Crystals are solids whose atoms or molecules occupy specific, ordered positions in space.

All natural gemstones except opal are crystalline, and many of them, such as diamond, ruby, sapphire and emerald, are found in the form of beautifully cut crystals.

To visually represent the structure of crystals, crystal lattices are used. The lattice nodes contain the centers of atoms or molecules of a given substance. Atoms in crystals are tightly packed, the distance between their centers is approximately equal to the size of the particles. In the image of crystal lattices, only the position of the centers of atoms is indicated.

In each crystal lattice, an element of minimal size can be distinguished, which is called a unit cell. The entire crystal lattice can be built by parallel transfer of the unit cell along certain directions. Examples of simple crystal lattices: 1 – simple cubic lattice; 2 – face-centered cubic lattice; 3 – body-centered cubic lattice; 4 – hexagonal lattice. Crystal lattices of metals often take the form of a hexagonal prism (zinc, magnesium), a face-centered cube (copper, gold), or a body-centered cube (iron).

The famous Russian crystallographer Evgraf Stepanovich Fedorov established that in nature only 230 different space groups can exist, covering all possible crystal structures. Most of them (but not all) are found in nature or created artificially.

Crystals can take the form of various prisms, the base of which can be a regular triangle, square, parallelogram and hexagon. Therefore, the crystals have flat edges. For example, a grain of ordinary table salt has flat edges that form right angles with each other. This can be seen by examining the salt with a magnifying glass.

Ideal crystal shapes are symmetrical. According to Evgraf Stepanovich Fedorov, crystals shine with symmetry. In crystals you can find various elements of symmetry: plane of symmetry, axis of symmetry, center of symmetry. A cube-shaped crystal (NaCl, KCl, etc.) has nine planes of symmetry, thirteen axes of symmetry, in addition, it has a center of symmetry. There are a total of 23 symmetry elements in the cube.

The correct external shape is not the only or even the most important consequence of the ordered structure of the crystal. The main property of crystals is anisotropy - this is the dependence of physical properties on the direction chosen in the crystal.

Crystals in different directions exhibit different mechanical strength. For example, a piece of mica easily delaminates in one direction into thin plates, but it is much more difficult to tear it in the direction perpendicular to the plates.

The graphite crystal is easily exfoliated in one direction. The layers are formed by a series of parallel networks consisting of carbon atoms. The atoms are located at the vertices of regular hexagons. The distance between the layers is relatively large - about 2 times the length of the side of the hexagon, so the bonds between the layers are less strong than the bonds within them.

The optical properties of crystals also depend on the direction. Thus, a quartz crystal refracts light differently depending on the direction of the rays incident on it. Many crystals conduct heat and electricity differently in different directions.

Metals have a crystalline structure. But if you take a relatively large piece of metal, then its crystalline structure is not manifested in any way, either in appearance or in its physical properties. Why do metals in their normal state not exhibit anisotropy?

It turns out that the metal consists of a huge number of small crystals fused together. Under a microscope or even with a magnifying glass it is not difficult to see them, especially on a fresh fracture of the metal. The properties of each crystal depend on the direction, but the crystals are randomly oriented relative to each other. As a result, all directions inside metals are equal and the properties of metals are the same in all directions.

Single crystals - single crystals have a regular geometric shape, and their properties are different in different directions.

A solid consisting of a large number of small crystals is called a polycrystal. Most crystalline solids are polycrystals, as they consist of many intergrown crystals.

Watch the video “Educational about crystals”

Task No. 1 group work

Consider a collection of minerals. Write down the name of minerals that have a crystalline structure.

Task No. 2 group work

The properties of crystals are used in various devices and instruments. You need to study information about the use of crystals. And record the results of the work in a table.

They use netbooks or hand out cards. "Annex 1"

We live on the surface of a solid body - the globe, in structures built from solid bodies. Tools and machines are also made of solids. But not all solids are crystals.In addition to crystalline bodies, there are amorphous bodies. Examples of amorphous bodies are resin, glass, rosin, sugar candy, etc.

Often the same substance can be found in both crystalline and amorphous states. For example, quartz SiO 2 can be in either crystalline or amorphous form (silica). Amorphous bodies do not have a strict order in the arrangement of atoms. Only the nearest neighboring atoms are arranged in some order. Amorphous bodies are similar to liquids in the arrangement of atoms and their behavior.

The crystalline form of quartz can be schematically represented as a lattice of regular hexagons. The amorphous structure of quartz also has the appearance of a lattice, but of irregular shape. Along with hexagons, it contains pentagons and heptagons. Amorphous bodies are solids where only short-range order in the arrangement of atoms is preserved."Slide 14"

Task No. 3 group work

Using the simulator, sort substances and determine whether they belong to crystals or amorphous bodies.

All amorphous bodies are isotropic, that is, their physical properties are the same in all directions. Under external influences, amorphous bodies exhibit both elastic properties, like solids, and fluidity, like liquids. Thus, under short-term impacts (impacts), they behave like solid bodies and, under a strong impact, break into pieces. But with very long exposure, amorphous bodies flow. You can see this for yourself if you are patient. Follow the piece of resin that is lying on a hard surface. Gradually the resin spreads over it, and the higher the temperature of the resin, the faster this happens.

Over time, a non-crystalline substance can “degenerate”, or, more precisely, crystallize; the particles in them gather in regular rows. Only the period is different for different substances: for sugar it is several months, and for stone it is millions of years. Let the candy lie quietly for two or three months. It will be covered with a loose crust. Look at it with a magnifying glass: these are small crystals of sugar. Crystal growth has begun in non-crystalline sugar. Wait a few more months - and not only the crust, but the entire candy will crystallize. Even our ordinary window glass can crystallize. Very old glass sometimes becomes completely cloudy because a mass of small opaque crystals forms in it.

Amorphous bodies at low temperatures resemble solid bodies in their properties. They have almost no fluidity, but as the temperature rises they gradually soften and their properties become closer and closer to the properties of liquids. This happens because with increasing temperature, jumps of atoms from one equilibrium position to another gradually become more frequent. Amorphous bodies, unlike crystalline ones, do not have a specific melting point. They do not have a constant melting point and are fluid. Amorphous bodies are isotropic; at low temperatures they behave like crystalline bodies, and at high temperatures they behave like liquids.

Task No. 4 group work

I suggest that you verify through experience that crystalline bodies have a certain melting point. Conduct a study of changes in the temperature of substances over time. Find out which of the bodies is crystalline and which is amorphous.

Record the measurement results in a table. "Appendix 2"

Summing up the experiment.

Large single crystals with their own regular shape are very rare in nature. But such a crystal can be grown under artificial conditions. Crystallization can occur from: solution, melt, gaseous state of a substance.

A crystal is usually grown from solution in this way

First, a sufficient amount of the crystalline substance is dissolved in water. In this case, the solution is heated until the substance is completely dissolved. The solution is then slowly cooled, thereby transferring it to a supersaturated state. A seed is added to the supersaturated solution. If, during the entire crystallization time, the temperature and density of the solution are maintained the same throughout the entire volume, then during the growth process the crystal will take the correct shape.

Presentation of the project prepared by students “Growing Crystals”

Primary consolidation.

Task No. 5 “Test yourself”

A 5-item test is built into the presentation.

Task No. 6 individual work

You can test your knowledge on the topic covered by answering the test questions. When completing the assignment, you can use the notes and educational information module “Amorphous and crystalline bodies”

Information module dedicated to the topic “Amorphous and crystalline bodies” in high school. In addition to illustrated hypertext materials, it includes an interactive model “Structure of Crystals”

Test

Reflection

YoursattitudeTolesson?

Waswhetherto youInterestingonlesson?

WhichwouldYouputto myselfassessmentbehindlesson?

Homework§ 75,76

Additional task. Creation of presentations “Use of crystals in everyday life”, “The largest crystals”, “Liquid crystals”, etc.

Literature

Physics: textbook for 10th grade. Authors: G.Ya. Myakishev, B.B. Bukhovtsev, N.N. Sotsky

M.: Education, 2010.

Crystals. Leontyev Pavel. http://www.stihi.ru/2001/09/01-282

The module contains cells with names of their structure type and formulas of some substances. The student is asked to distribute the proposed substances according to the type of their structure by transferring the formula to the appropriate cell.

The information module is devoted to the topic “Amorphous and crystalline bodies” of secondary school. In addition to illustrated hypertext materials, it includes an interactive model “Structure of Crystals”

Test , includes 6 interactive tasks of various types with the possibility of automated verification for certification on the topic “Amorphous bodies. Crystal bodies" high school

Description of the presentation by individual slides:

1 slide

Slide description:

2 slide

Slide description:

Similarities and differences. In physics, only crystalline bodies are usually called solids. Amorphous bodies are considered to be very viscous liquids. They do not have a specific melting point; when heated, they gradually soften and their viscosity decreases. Crystalline bodies have a certain melting point, unchanged at constant pressure. Amorphous bodies are isotropic—the properties of the bodies are the same in all directions. Crystals are anisotropic. The properties of crystals are not the same in different directions.

3 slide

Slide description:

Crystals. Studying the internal structure of crystals using X-rays made it possible to establish that the particles in the crystals have the correct arrangement, i.e. form a crystal lattice. - The points in the crystal lattice corresponding to the most stable equilibrium position of the particles of a solid are called crystal lattice nodes. In physics, a solid means only those substances that have a crystalline structure. There are 4 types of crystal lattice: ionic, atomic, molecular, metal. 1. the nodes contain ions; 2.atoms; 3.molecules; 4.+ metal ions

4 slide

Slide description:

Amorphous bodies. Amorphous bodies, in contrast to crystalline bodies, which are characterized by long-range order in the arrangement of atoms, have only short-range order. Amorphous bodies do not have their own melting point. When heated, an amorphous body gradually softens, its molecules change their nearest neighbors more and more easily, its viscosity decreases, and at a sufficiently high temperature it can behave like a low-viscosity liquid.

5 slide

Slide description:

Types of deformation. A change in the shape and size of a body is called deformation. The following types of deformation exist: 1. deformation of longitudinal tension and longitudinal compression; 2. deformation of all-round tensile and all-round compression; 3.transverse bending deformation; 4.torsional deformation; 5.shear deformation;

6 slide

Slide description:

Each of the described types of deformation may be greater or lesser. Any of them can be assessed by absolute deformation ∆a numerical change in any size of a body under the influence of force. Relative deformation Ɛ (Greek epsilon) is a physical quantity that shows what part of the original size of the body a is the absolute deformation ∆a: Ɛ=∆L/L Ɛ= ∆a / a Mechanical stress is a quantity characterizing the action of internal forces in a deformed solid. σ= F / S [Pa]

7 slide

Slide description:

Hooke's law. Elastic modulus. Hooke's law: mechanical stress in an elastically deformed body is directly proportional to the relative deformation of this body. σ=kƐ The value k, which characterizes the dependence of mechanical stress in a material on the type of the latter and on external conditions, is called the elastic modulus. σ=EƐ σ=E (∆L/L) E – elastic modulus “Young’s modulus”. Young's modulus is measured by the normal stress that must arise in the material when a relative deformation equal to unity, i.e. when the sample length is doubled. The numerical value of Young's modulus is calculated experimentally and entered into the table. Thomas Young