States of Matter

1. States of Matter A Kinetic Experience

2. Kinetic Theory of MatterAlso known as the Molecular theory of matter: • All matter is made of molecules and atoms that act like tiny particles • Molecules are always in motion. The higher the temperature, the faster the particles move • At the same temperature, heavier particlesmove slower than lighter particles.

3. Balls in Box Demo • Small vibrations = Solid • More Energy Added in the form of heat energy, bouncing inside box = Liquid • Even More Energy Added in the form of heat energy, balls falling out of box = Gas (evaporation) Heavier molecules evaporate at a slower rate. • Putting the balls back into the box = Condensation

4. Why metal balls inside some of the tennis balls? • Heavier molecules take more energy to evaporate. • Lighter molecules evaporate more readily. • Video – Kinetic Molecular Theory Watch as the water molecules gain enough kinetic energy to evaporate.

5. How does thermal energy affect the state of a substance? • Thermal Energy interactive Video – Investigate at home • Video molecules in motion

6. Temperature • Temperature is the average kinetic energy of the atoms (or molecules) in a system. Temperature measures how “hot” something is.

7. Temperature Scales • Fahrenheit English system • Water freezes at 32 degrees Fahrenheit and boils at 212 degrees. • Celsius modern system • freezing point of water 0 degrees Celsius, and the boiling point 100 degrees Celsius. • Kelvin A scale that is based on energy content . • At zero Kelvin (absolute zero) all molecular motion stops. • Scientists have figured out a way to get a temperature only a few billionths of a degree above absolute zero.

9. 5 States of Matter • Elements and compounds can move from one phase to another when specific physical conditions are present. • When the temperature of a system goes up, the matter in the system becomes more excited and active. • As the temperature rises, matter moves to a more active state.

10. 5 States of Matter • Bose-Einstein Condensates (BEC) • Solids • Liquids • Gases • Plasmas • Each of these states is also known as a phase.

11. Bose-Einstein Condensate • In 1995, two scientists, Cornell and Weiman, created the condensate. • Two other scientists, Satyendra Bose and Albert Einstein, had predicted it in the 1920s, but they didn't have the equipment and facilities to make it happen at that time. • BECs can only be created with a few special elements. Cornell and Weiman did it with rubidium (Rb).

12. Bose-Einstein condensate (BEC) • Super unexcited and super cold atoms. • Colder than solids • Occur at temperatures near absolute 0 ((0 K, −273.15 °C, or −459 °F ) • Atoms begin to clump - no more energy to transfer • creating a "super atom." The atoms take on the same qualities and become one blob – No longer separate atoms

13. What is a solid? • Solids have a • definite shape • definite volume. • Molecules are tightly packed • Cannot move freely, can only vibrate • Molecules stay fairly still. • Energy and temperature are very low

14. Draw a Solid.

15. Solids are broadly characterized as • Crystalline Solids- Repeating pattern Examples Ghost crystals crystals in rocks Salt rock candy Copper Sulfate • Amorphous Solids- - Non-repeating pattern Examples Wax play dough hand putty peanut butter Gum clay

16. What is a liquid? Liquids have • no definite shape, take shape of container in which it is held • Definite or fixed volume. • Molecules are closely packed • Molecules vibrate and slide around one another easily. • Energy and temperature, in comparison to a solid, are higher • The force of attraction between these particles is called intermolecular forces. These force cause liquid particles to be fairly close together, thus raising the density of a liquid compared to a gas. A misconception that molecules do not touch in a liquid. Demo Examples: Water in different sized containers. Water in syringe Water in baggie.

17. Draw a liquid.

18. Solid/LiquidCheck-Up • Describe particle motion in a solid. • Describe particle motion in a liquid. • What are two different types of solids? Give 1 example of each. • What is a common misconception about liquids?

19. What is a Gas? • Gases have indefinite and unstable shape • No definite volume, volume determined by container • Molecules can vibrate, slide, spin, and bounce off of one another. • Molecules are far apart and can move around quickly. • Energy and temperature are the higher than those of both solids and liquids • Gases diffuse (The movement of particles from a region of high concentration to a region of low concentration) . • Heat will increase the rate of diffusion. Examples: Perfume Lysol “tooting your little horn” Ammonia

20. Did you know that Gases were also called fluids? Why? Draw a gas.

21. Vapor vs. Gas • Vapor and gas mean the same thing. • The word vapor is used to describe gases that are usually found as liquids. • Good examples are water (H2O) or mercury (Hg). Water and mercury are liquids at room temperature, so they get the vapor title when they are in a gaseous phase.  • Compounds like carbon dioxide (CO2) are usually gases at room temperature, so scientists will rarely talk about carbon dioxide vapor. Water Vapor from a geyser

22. Compressed Gases With very little pressure, gas molecules can be compressed. Examples • compressed air in a spray bottle • When you feel the carbon dioxide rush out of a can of soda. • These gas were forced into a smaller space so the gas escapes the first chance it gets. • The gas molecules move from an area of high pressure to one of low pressure.

23. What is plasma? • Charged particles --Ionized Gas-- a cloud of protons, neutrons and electrons where all the electrons have come loose from the atoms • This is an extreme gas! Strikes the other atoms so forcefully it knocks off an electron! • These gases • vibrate, • Slam into one another causing bright gases, • lots of heat • lots of energy. • Hotter than gas. A plasma occurs when the temperature is between 1000 degrees C and 1,000,000,000 degrees C

24. Plasma Examples Neon Signs Our Sun, the core of stars Lightning Plasma TV Aurora Borealis plasma balls Human Christmas Tree Plasma Cutters

25. Draw plasma.

27. Gas/Plasma Check-Up • Describe particle motion in a gas. • Describe particle motion in plasma. • What is another name for plasma? • How is plasma formed?

29. A Phase Change • A "phase" describes a physical state of matter. • The key word to notice is physical. • If energy is added (like increasing the temperature) or if energy is taken away (like freezing something), you have created a physical change.

30. A Phase Change • A compound or element can move from one phase to another, but still be the same substance. • It may require extreme temperatures or extreme pressures, but it can be done. 

32. Melting • The change of state from solid to liquid • Melting Point - the temperature at which matter changes from solid to liquid, (e.g. The melting point of water from ice to liquid water is 0 °C)

33. Evaporization • Matter changing from a liquid to a gas. • Energy is added to the system. • Boiling Point - the temperature at which matter changes from a liquid to a gas, (e.g. The boiling point of water from liquid water to steam is 100 °C)

34. Boiling vs. Evaporation

35. Evaporation How does evaporation differ from vaporization?

36. Boiling vs. Evaporation

37. Pressure and Phase Change • If lowering the temperature won’t get a liquid to change to a solid just apply pressure. • By applying pressure you are “pushing” the molecules together. • Example • To change Liquid Nitrogen (N2) to a solid pressure must be applied.

38. Temperature and Pressure • Phet- Use this interactive model to learn more about how temperature and pressure are related. Click to run

39. Evaporative Cooling • When high energy particles escape a liquid, the average energy of the remaining particles is less so the liquid cools. • The cool liquid then cools the surface on which it is resting. Examples: • Joggers cooling down as their sweaty clothes dry out • Water cools down a roof on hot summer day • A wet cloth is placed on your forehead when you have a fever

41. Review Questions • How does temperature effect state change? • Why does alcohol evaporate more quickly than water? • When butane changes from a liquid to a gas is energy released or absorbed? • Why did the flaming money remain unharmed when it was caught on fire?

42. Sublimation Matter changing from a solid directly to a gas. (skipping the liquid phase) Examples: Dry Ice (frozen Carbon Dioxide) Snow in parking lot that does not melt Mothballs in closet Old ice cubes in freezer

43. Condensation • Matter changing from a gas to a liquid. Examples: Glass of ice water Bathroom mirror after shower Hot breath on bus window Dew on grass.

44. Freezing or Solidification • the change of state from liquid to solid Water is the only known substance that expands as it freezes. Most Substances contract.

45. Deposition • Matter changing from a gas directly to a solid. (Skipping the liquid phase) Examples: Frost on glass- Water vapor becoming a solid Demo – Mothballs on a hotplate making crystals.

47. Thermal Expansion • Thermal expansionis the tendency of a matter to change in volume in response to a change in temperature. Examples: Sidewalk cracking Doorway Cracks in house foundation

49. Heating and Cooling Curves • Heating Curve Link

50. Hotplate Activity