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# Chapter 9

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States of matter
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# Chapter 9

Physics for 9th grade students at Jubilee school

Physics for 9th grade students at Jubilee school

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## Weitere Verwandte Inhalte

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### Chapter 9

1. 1. Chapter 9 “The Kinetic Model of Matter” Matter is anything that has a mass and takes up a space. It is everything around us. What is Matter:
2. 2. Physical STATES OF MATTER  There are 5 states of matter: Solids, liquids, gases, plasmas, Bose-Einstein condensates (BEC). These different states (phases) have different physical properties.
3. 3. States of Matter 1. The molecules of solid are locked in a rigid structure and can only vibrate. (Add thermal energy and the vibrations increase.) A solid has definite volume and shape. * Some solids are crystalline, like table salt (NaCl), in which the atoms are arranged in a repeating pattern.
4. 4. 2. A liquid is in general incompressible, so it has a definite volume but no definite shape, if you pour a liter of juice into several glasses, the shape of the juice has changed but the total volume hasn’t. 3. A gas is easily compressed. It has neither definite shape nor definite volume, If a container of CO2 is opened, it will diffuse throughout the room.
5. 5. 4. *A plasma is an ionized gas and is the most common form of matter in the universe, since the insides of stars are plasmas.
6. 6. Another example of plasma is a “neon sign”. Just like fluorescent lights, neon signs are glass tubes filled with gas. When the light is turned on, the electricity flows through the tube. The electricity charges (ionizes) the gas and creates plasma inside of the tube. The plasma glows a special color depending on what kind of gas is inside.
7. 7. 5. * BOSE-EINSTEIN CONDENSATE (BEC)  Particles are extremely close together.  Particles barely move.  Only found at extremely cold temperatures (close to absolute zero)  Lowest energy of the 5 states of matter https://www.youtube.com/watch?v=J9_LmSTtpkI
8. 8. Fluids The term fluid refers to gases and liquids. Gases and liquids have more in common with each other than they do with solids, since gases and liquids both have particles that are free to move around. They are not locked in place as they are in a solid. The hotter the fluid, the faster its molecules move, and the more space the fluid will occupy.  Also, unlike solids, fluids can flow.
9. 9. Does Heat Affect Matter? Yes, it changes the state of matter.
10. 10. Phase (state) Changes Evaporation: Liquid  Gas Condensation: Gas  Liquid Melting: Solid  Liquid Freezing: Liquid  Solid *Sublimation: Solid  Gas * Examples of sublimation: • Dry ice (frozen CO2) goes directly from the solid to the gaseous state (it sublimates). This creates an eerie. • Comets are very small objects containing frozen gases that sublimate when the comet get close enough to the sun. This creates the characteristic tail the can be millions of miles long.
11. 11. * Deposition occurs when a gas becomes a solid without going through the liquid state of matter. Those who live close to the earth poles can see frost on winter mornings. Those little frost crystals on plants build up when water vapor from the air becomes a solid on the leaves of plants.
12. 12. KINETIC THEORY Also known as “The Kinetic Model of Matter” • Kinetic Theory states that the tiny particles in all forms of matter are in constant motion.  3 Principles of Kinetic Theory: • All matter is made up of tiny particles. • These particles are in constant motion. • The collisions of particles (with each other or with the container), are perfectly elastic.
13. 13. https://www.youtube.com/ watch?v=hy-clLi8gHg Brownian motion (movement) The irregular motion of the minute particles of matter suspended in a fluid. It was named for the Scottish botanist Robert Brown, who observed (1827) the movement of plant spores floating in water. This is due to the constant irregular motion of the molecules of the fluid, kicking the small particles of matter.
14. 14. Fast Facts about Heat  The boiling point is the temperature at which a substance changes from a liquid to a gas.  How does it happen? When a liquid is heated, its particles move faster and faster until they break the bonds with other particles and escape from the liquid. http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks 3/science/changing_matter/index.htm
15. 15. Freezing  The freezing point is the temperature at which a substance changes from a liquid to a solid.  How does this happen? Particles loose energy, they move slower, then they become closer together and solidifies (forms a solid).
16. 16. Exothermic Phase Changes Release Heat Energy Endothermic Phase Changes Absorb Heat Energy • Freezing • Condensation • Deionization (from plasma to gas) •Melting • Boiling • Ionization (from gas to plasma) Phase changes that release energy are exothermic. Phase changes that absorb energy are endothermic. Notice that the freezing point and melting point are at the same temperature. Condensation and boiling occur at the same temperature. * Exothermic and Endothermic
17. 17. * Pressure & Freezing It’s easier to freeze most liquids if they’re subjected to very high pressures. In order to turn a liquid into a solid, the molecules must get close enough together. High pressure can force the molecules closer together, to freeze the liquid, even if it’s not cold enough. BUT … 
18. 18. Water is an exception to this because, due to its molecular shape, it expands upon freezing. So, squeezing water makes freezing it harder. The pressure on ice due to a passing skater can actually melt a small amount of the ice.
19. 19. * Pressure & Boiling The lower the pressure on a liquid, the easier it is to make it boil. Water, for example, boils at temperatures below 100ºC up in the mountains where the air pressure is lower.  It takes longer to cook food in boiling water at high altitudes; because the boiling water is not as hot as it usually is.  In a vacuum water will boil at any temperature since there is no pressure at the surface to prevent the water from vaporizing…
20. 20. It’s harder for a liquid to vaporize when it is subjected to high pressure, since gases take up more space than liquids. At high pressure, water boils at a high temp. In a pressure-cooker water can remain liquid up to 120 ºC, and the hotter water can cook food faster. https://www.youtube.com/ watch?v=I5mkf066p-U *… Pressure & Boiling
21. 21. *Freezing of Solutions The freezing point of a solution, such as salty water, is lower than the freezing point for the solvent by itself (pure water). The higher the concentration of the solute (salt), the more the freezing point is lowered. This is because the “foreign” molecules or atoms of a solute interfere with the molecules of the solvent.
22. 22. boiling vs. evaporation  Evaporation takes place only at the surface of a liquid or solid, while boiling takes place throughout the liquid.  Boiling occurs at the boiling temperature, evaporation takes place at any temperature.  Particles that have “higher kinetic energy” escape and become vapor (gas)…
23. 23. * Factors of the rate of evaporation:
24. 24. Gases and the Kinetic theory • The kinetic theory of gases describes a gas as a large number of small particles (atoms or molecules), all of which are in constant, random motion. The rapidly moving particles constantly collide with each other and with the walls of the container.
25. 25. Boyle’s Law: • In 1662 Robert Boyle discovered that “In constant temperature, pressure and volume of a given amount of gas are inversely proportional,” • A given amount of gas means a fixed mass or number of molecules. •https://www.youtu be.com/watch?v=N 5xft2fIqQU •https://www.youtu be.com/watch?v=2 7yqJ9vJ5kQ
26. 26.  Boyle's Law Formula is expressed symbolically as Another way to express Boyle's Law Formula is or  Where:  P is pressure of the gas  V is volume of the gas  k is a constant, it’s units are Pa*m3 , or N*m
27. 27. Boyle's Law Problems  Question 1: A sample of gaseous nitrogen in a 65.0 L automobile air bag has a pressure of 700 mm Hg. If this sample is transferred to a 25.0 L bag at the same temperature. what is the pressure of the gas in the 25.0 L bag?  Question 2: A sample of neon (Ne) occupies 4.00L at a pressure of 5.00 × 104 Pa and a temperature of 273K. Determine the volume of the sample at 100KPa?  Answers: (1) P1 = 1820 mm Hg, (2) V2 = 2 L
28. 28. http://mrtremblaycambridge.weebly.com/p4-simple- kinetic-molecular-model-of-matter.html