Slide 2
Amorphous bodies are bodies that gradually soften when heated and become more viscous.
Slide 3
Solids
Crystalline Amorphous - Does not have a crystal lattice; -Do not have a melting point; -Isotropic; -Have fluidity; -Able to transform into crystalline and liquid states; -They only have short-range order. Examples are glass, sugar candy, resin.
Slide 4
The structure of amorphous bodies. Research using an electron microscope shows that in amorphous bodies there is no strict order in the arrangement of their particles. Take a look at the picture showing the arrangement of particles in amorphous quartz. These substances consist of the same particles - molecules of silicon oxide SiO2. Particles of amorphous bodies vibrate continuously and randomly. They can jump from place to place more often than crystal particles. This is also facilitated by the fact that the particles of amorphous bodies are located unequally densely: there are voids between them.
Slide 5
Melting of amorphous bodies. As the temperature increases, the energy of the vibrational motion of atoms in a solid increases and, finally, a moment comes when the bonds between atoms begin to break. In this case, the solid turns into a liquid state. This transition is called melting. At a fixed pressure, melting occurs at a strictly defined temperature. The amount of heat required to transform a unit mass of a substance into a liquid at the melting temperature is called the specific heat of fusion λ. To melt a substance of mass m, it is necessary to expend an amount of heat equal to: Q = λ m. Melting process amorphous bodies differs from the melting of crystalline bodies. As the temperature increases, amorphous bodies gradually soften and become viscous until they turn into liquid. Amorphous bodies, unlike crystals, do not have a specific melting point. The temperature of amorphous bodies changes continuously. This happens because in amorphous solids, as in liquids, molecules can move relative to each other. When heated, their speed increases, and the distance between them increases. As a result, the body becomes softer and softer until it turns into liquid. When amorphous bodies solidify, their temperature also decreases continuously.
Slide 1
Amorphous bodies
Slide 2
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).
Slide 3
Observation of the crystal structure of certain substances
salt
quartz
diamond
mica
Slide 4
1. Amorphous bodies do not have a specific melting point
2. Amorphous bodies are isotropic, for example:
paraffin
plasticine
The strength of these bodies does not depend on the choice of test direction
paraffin
glass
Slide 5
Demonstration of evidence of the properties of amorphous bodies
3. With short-term exposure they exhibit elastic properties. For example: rubber balloon
4. Under prolonged external influence, amorphous bodies flow. For example: paraffin in a candle.
5. Over time, they become cloudy (n/r: glass) and devitrify (n/r: sugar candy), which is associated with the appearance of small crystals, the optical properties of which differ from the properties of amorphous bodies
Slide 6
Slide 7
Amorphous bodies
An amorphous body is a solid body that does not have a fixed melting point, and there is no real order in the arrangement of particles.
Slide 8
When heated, amorphous bodies gradually soften and finally turn into liquid. Their temperature changes continuously.
Slide 9
the same substance can be in both crystalline and amorphous states
What happens if you melt sugar and then let it cool and harden? It turns out that if the melt cools slowly, then crystals form when it solidifies; if cooling occurs very quickly, amorphous sugar or candy. On a candy of amorphous sugar, a loose crust appears over time. Look at it through a magnifying glass or under a microscope, and you will see that it consists of tiny sugar crystals: amorphous sugar has begun to crystallize.
Slide 10
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 unchanged when rotated, for example:
plasticine
paraffin
Slide 11
Demonstration of evidence of the properties of amorphous bodies
3. With short-term exposure they exhibit elastic properties. For example: rubber balloon
4. Under prolonged external influence, amorphous bodies flow. For example: paraffin in a candle.
5. Over time, they become cloudy (n/r: glass) and devitrify (n/r: sugar candy), which is associated with the appearance of small crystals, the optical properties of which differ from the properties of amorphous bodies
Slide 12
Over time, amorphous substances degenerate into crystalline ones. Only the time frame for different substances is different: for sugar this process takes several months, and for stones millions of years
The amorphous structure of a substance has the appearance of a lattice, but is not of regular shape
“Study of the movement of a body in a circle” - Dynamics of the movement of bodies in a circle. Movement of bodies in a circle. A basic level of. P.N. Nesterov. Decide for yourself. We check the answers. Studying the problem solving method. Algorithm for solving problems. Run the test. Body weight. Solve the problem.
"Reactive Systems" - Humanity will not remain on Earth forever. Soviet rocket system. Jet motion in nature. Squid. Jet propulsion in technology. Two-stage space rocket. Konstantin Eduardovich Tsiolkovsky. Law of conservation of momentum. "Katyusha". Sergei Pavlovich Korolev. Squid can be delicious. Jet propulsion.
“Conductivity of semiconductors” - Questions for control. Conductivity of silicon-based semiconductors. Full-wave rectifier circuit. Consider the electrical contact of two semiconductors. Reverse inclusion. The main property of the p–n junction. Half-wave rectifier circuit. Different substances have different electrical properties. Changes in semiconductor. Electric current in various environments. P–n junction and its electrical properties.
“Field strength” - Which arrow in the figure indicates the direction of the electric field strength vector. Electric field. Field strength. The principle of superposition of fields. What is the direction of the electric field strength vector. Indicate the point at which the field strength can be zero. Creators of electrodynamics. Field strength of a point charge. The tension at point O is zero. The electrostatic field is created by a system of two balls.
“Types of lasers” - Liquid laser. Solid state lasers. Chemical laser. Classification of lasers. Ultraviolet laser. Source of electromagnetic radiation. Semiconductor laser. Laser. Application of laser. Properties of laser radiation. Amplifiers and generators. Gas laser.
“Heat engines” 10th grade” - Team members. Steam turbine. Protection of Nature. Engine efficiency. A little about the creator. Tsiolkovsky. Three-wheeled stroller invented by Karl Benz. James Watt. Steam engines and steam turbines have been and are being used. Diesel engines. Rocket engine. The engine operates on a four-stroke cycle. For those who want to reach the stars. Denis Papin. Archimedes. The principle of operation of the turbine is simple. Types of internal combustion engines.
“Cycle of matter” - Phosphorus cycle. Nitrogen cycle. Living matter plays an important role in the transformations of phosphorus. The source of nitrogen on Earth was volcanic NH3, oxidized O2. Organisms extract phosphorus from soils and aqueous solutions. Carbon cycle. CO2 from the atmosphere is assimilated during photosynthesis and converted into organic compounds of plants.
“Gas laws” - Under normal conditions (temperature 0°C and pressure - 101.325 kPa), the molar volume of any gas is a constant value equal to 22.4 dm3/mol. Normal conditions: temperature - 0°C pressure - 101.325 kPa. 1. What is stoichiometry? 2. What laws did you learn about in the last lesson? Gay-Lussac (1778-1850) At constant temperature and pressure, the volumes of reacting gases relate to each other, as well as to the volumes of the resulting gaseous products, as small whole numbers.
“Crystalline and amorphous substances” - White phosphorus P4. There are molecules at the lattice sites. Gas. Examples: simple substances (H2, N2, O2, F2, P4, S8, Ne, He), complex substances (CO2, H2O, sugar C12H22O11, etc.). Atomic crystal lattice. Graphite. Crystal lattices. Developed by E.S. Pavlova, a chemistry teacher at the Municipal Educational Institution “Lyceum No. 5” in Orenburg. - 194°.
“Simple substances - non-metals” - Non-metals include inert gases. Diamond. Gases - nonmetals - diatomic molecules. Allotropy of sulfur. The structure of the outer electron layer of helium and neon atoms. Application of helium. Allotropy of carbon. To the begining. Use of argon. Allotropy of oxygen. Liquid substances are non-metals. Cl2. Further. Crystalline, plastic and monoclinic.
“Great cycle of substances” - Products. 1. 3. Cycle of substances. Pure water. 4. M o u r s h i k i s. R. O. B. 2. Feeders. F. Crossword. E d o k i. Topic: large cycle of substances. A. Clean air.
“Melting and solidification” - A.P. Chekhov “Student”. A. S. Pushkin “Ruslan and Lyudmila.” Remember! Learn to understand the essence of such thermal phenomena as melting and crystallization. There is a temperature above which a substance cannot be in a solid state. Crystallization (hardening). I'll have to leave, but where, one wonders?
There are a total of 25 presentations in the topic