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Entrance question

Entrance question. Can energy be created or destroyed? Can matter be created or destroyed?. Ch 3-1 . Physical Science. Kinetic Theory. All matter is made of atoms and molecules that act like tiny particles

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Entrance question

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  1. Entrance question • Can energy be created or destroyed? • Can matter be created or destroyed?

  2. Ch 3-1 Physical Science

  3. Kinetic Theory • All matter is made of atoms and molecules that act like tiny particles • These particles are always in motion. The higher the temperature, the faster the movement • At same temperature, heavier particles move slower than lighter ones

  4. Solids • Definite volume and shape • Low energy state • Molecular movement is small vibrations • Crystalline • Orderly arrangement of atoms • Amorphous • No order to atoms but still tightly packed

  5. liquids • Definite volume not shape • Medium energy • Molecular movement is more quickly

  6. gasses • No definite volume or shape • They are form filling • High energy • Molecules move very quickly in any direction

  7. plasma • Most common state of matter in the universe • Stars, lightning, fire, northern lights, neon signs • No definite shape • Conduct electricity, electric and magnetic fields affect them

  8. Gas Laws

  9. Properties of Gases • Gases have no definite volume or shape • Gas particles move rapidly in all directions • Gases are fluids • Gas molecules are in constant motion and frequently collide with their surroundings • Gases have low density because their molecules are so spread out • Gases are compressible • Gases spread out easily and mix with one another readily

  10. 2 Gas Laws • Boyle’s Law – pressure and volume • Charles’s Law – temperature and volume

  11. Boyle’s Law • Relationship between gas pressure and volume • Temperature stays constant • For a fixed amount of gas at a constant temperature, the volume of gas increases as its pressure decreases. volume : Pressure

  12. Charles’s Law • Relationship between temperature and volume • Fixed amount of gas • Constant pressure • For a fixed amount of gas at a constant pressure, the volume of the gas increases as temperature increases temperature: volume

  13. Section 3-2: Phase Changes

  14. Entrance Question • If a balloon were to be place in the freezer what would happen? Explain why and name which law this follows. • If two substances have the same size and one substance weighs 5.2 g and the other substance weighs 2.4 g which substance is more dense? How do you know? • Name 4 properties of all gasses.

  15. Phase/State Change • A change of state- the conversion of a substance from one physical form to another is known as a physical change. Does not change the identity of the substance

  16. Phase/State Change • A transfer of energy known as heat causes the temperature of a substance to change which can lead to a change in state. • Substances can be made to change state by adding or taking away energy.

  17. Energy and Changes of State • To take place some changes in state require energy. • Vaporization  liquid to a gas • Particles in a liquid absorb enough energy to escape the liquid phase. • Both evaporation and boiling are types of vaporization.

  18. Vaporization-Evaporation • Evaporation from liquid to gas. • Occurs at temperatures below the boiling point. • Happens only at the surface of the substance.

  19. Vaporization-Boiling • Boiling  liquid to gas • Occurs at or above the boiling point. • Happens throughout the liquid. • Boiling Point – The temperature at which a liquid changes to a gas.

  20. Other Changes of State • Melting  solid to a liquid • Melting Point-The temperature at which a solid changes to a liquid is called the melting point.

  21. Other Changes of State • Sublimation  solid directly to gas without going through liquid • Dry ice is a good example of sublimation.

  22. Energy and Changes of State • Energy may also be released by some changes in state. • Condensation gas to liquid • Energy is released from the gas particles as they slow down

  23. Energy and Changes of State • Freezing  liquid to solid • Freezing Point -The temperature at which a substance changes from a liquid to a solid. • Freezing & Melting Points are the same.

  24. Energy and Changes of State • Deposition  gas to a solid

  25. Change of state vs. energy Add energy Release energy vaporization Add energy Add energy Release energy

  26. Energy and Changes of State • When a substance gains or loses energy, either its temperature changes or its state changes, but not both. • The temperature does not change when a substance is going through a phase change.

  27. Energy terms • Endothermic – change that requires energy • Melting, sublimation, evaporating • OR Feels cold to the touch • Exothermic – change that releases energy • Freezing, condensing • OR Feels warm to the touch

  28. Temperature & Phase Change • When a substance is… • below the freezing/melting point, it’s a solid. • between the freezing/melting point & the boiling point, it’s a liquid. • Above the boiling point, it’s a gas.

  29. Temperature changes OR phase change

  30. Section 3-3 Chemical Properties and Changes

  31. Physical Properties • Are usually easy to see. • A difference in color, shape, hardness, and volume of solids can all be easily be seen or felt.

  32. Chemical Properties • The properties that describe how a substance changes into other new substances.

  33. Chemical Properties vs. Chemical Change • A chemical property describes a substance’s ability to change into a different substance. • Example: Flammability – chemical property that describes substances ability to burn.

  34. Chemical Properties vs. Chemical Change • A chemical change is the process by which the substance changes into another substance. • The substance cannot be changed back without going through another chemical change

  35. Chemical Changes • Burning (Combustion)/Explosions • Spoiling/Rotting • Cooking/Baking Examples: Fireworks, frying eggs, burning paper, leaves changing color.

  36. Signs of Chemical Change • Color changes • Bubbling, fizzing or foaming (gas is being released) • Production of sound, heat, light (release of energy) • Odor • Formation of a solid (precipitate).

  37. Chemical Properties vs. Chemical Change • Recall: When a substance undergoes a physical change it remains the same substance. • Note: When a substance undergoes a chemical change, or chemical reaction, it turns into a new and different substance.

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