Solids, Liquids, and Gases

1. Solids, Liquids, and Gases Chapter 16 Section 1 Kinetic Theory

2. Solids, Liquids, and Gases • Section 1 Kinetic theory slides 3-47 • Section 2 Properties of Fluids slides 50-64 • Section 3 Behavior of Gases slides 65-80

3. 1 Kinetic Theory of Matter • Kinetic theory • How particles move in the four states of matter • How particles behave at the melting point and boiling points

4. Kinetic Theory • Explains how particles of matter behave using three basic assumptions: • 1) All matter is composed of small particles- atoms, molecules and ions.

5. Kinetic Theory • Explains how particles of matter behave using three basic assumptions: • 1) All matter is composed of small particles- atoms, molecules and ions. • 2) These particles are in constant motion. The motion has no pattern.

6. Kinetic Theory • Explains how particles of matter behave using three basic assumptions: • 1) All matter is composed of small particles- atoms, molecules and ions. • 2) These particles are in constant motion. The motion has no pattern. • 3) These particles are colliding or crashing into each other and into the walls of the container.

7. Thermal Energy • Thermal energy is the total energy of the particles in a material including both potential and kinetic. • When the temperature is lowered, its particles will have less TE and will vibrate more slowly.

8. Average Kinetic Energy • Temperature is the average KE of particles in a substance. • The molecules in a solid randomly vibrate with temperature a measure of their average kinetic energy.

9. Average Kinetic Energy • Temperature is the average KE of particles in a substance. • The molecules in a solid randomly vibrate with temperature a measure of their average kinetic energy.

10. How do solids become liquids? • Melting point is the temperature at which a solid begins to turn into a liquid.

11. How do solids become liquids? • Melting point is the temperature at which a solid begins to turn into a liquid. • Energy is needed for the particles in a solid to slip out of their ordered arrangement.

12. How do solids become liquids? • Melting point is the temperature at which a solid begins to turn into a liquid. • Energy is needed for the particles in a solid to slip out of their ordered arrangement. • Heat of fusion is the amount of energy needed to change a substance from a solid to a liquid at its melting point.

13. Why do liquids flow? • Particles in liquids have more KE allowing them to overcome their attraction and slide past each other more readily. • This is why liquids flow and take the shape of their container; however, they still cling together and have a definite volume.

14. What is a gas state? • Gas particles have enough KE to overcome the attractions among them so that they have no fixed volume or shape.

15. What is a gas state? • Gas particles have enough KE to overcome the attractions among them so that they have no fixed volume or shape. • They can spread far apart or move close together to fill a container.

16. What is a gas state? • Gas particles have enough KE to overcome the attractions among them so that they have no fixed volume or shape. • They can spread far apart or move close together to fill a container. • If particles in a liquid move fast enough they can enter the gas state in a process called vaporization by evaporation or boiling.

17. How do liquids evaporate? • Evaporation is vaporization that occurs at the surface of a liquid. • It can occur below the liquid’s boiling point if particles at the surface have enough KE to escape liquid’s attractive force.

18. How does boiling vaporize liquids? • Boiling occurs at a specific temperature which depends on the pressure on the surface of the liquid.

19. How does boiling vaporize liquids? • Boiling occurs at a specific temperature which depends on the pressure on the surface of the liquid. • Air exerts pressure on the surface of the liquid which keeps particles from escaping the liquid.

20. How does boiling vaporize liquids? • The boiling point of a liquid is the temperature at which the pressure of the vapor in the liquid is equal to the external pressure on the surface of the liquid.

21. How does boiling vaporize liquids? • The boiling point of a liquid is the temperature at which the pressure of the vapor in the liquid is equal to the external pressure on the surface of the liquid. • Particles need energy to overcome the force of pressure.

22. How does boiling vaporize liquids? • Heat of vaporization is the amount of energy needed for the liquid at its boiling point to become a gas.

23. Why do gases fill their containers? • Gas particles move so quickly & are so far apart that they overcome the attractive forces among them; therefore, gases do not have a definite shape or a definite volume.

24. Why do gases fill their containers? • Gas particles move so quickly & are so far apart that they overcome the attractive forces among them; therefore, gases do not have a definite shape or a definite volume. • Diffusion is the spreading of particles throughout a given volume until they are evenly distributed.

25. What is the heating curve of a liquid?

26. What is the heating curve of a liquid? • The graph slopes upward when the KE is rising. • At B & D the graph is a horizontal line showing water temperature does not change.

27. What is the heating curve of a liquid? • At what temp is the water turning into a gas?

28. What is the heating curve of a liquid? • At 0°C, ice is melting.

29. What is the heating curve of a liquid? • At 0°C, ice is melting. • All of the energy put into ice at this temp is used to overcome the attractive forces among the particles in the solid.

30. What is the heating curve of a liquid? • At 0°C, ice is melting. • All of the energy put into ice at this temp is used to overcome the attractive forces among the particles in the solid. • After melting, the particles move more freely and their temp begins to rise.

31. What is the heating curve of a liquid? • At 100°C, water is boiling or vaporizing.

32. What is the heating curve of a liquid? • At 100°C, water is boiling or vaporizing. • The temperature stays the same again until the attractive forces are overcome.

33. What is the heating curve of a liquid? • At 100°C, water is boiling or vaporizing. • The temperature stays the same again until the attractive forces are overcome. • Then energy returns to raising the temperatures of the particles.

34. What is the plasma state? • Much of the matter in the universe is plasma, matter made up of positively and negatively charged particles with an overall neutral charge.

35. What is the plasma state? • Much of the matter in the universe is plasma, matter made up of positively and negatively charged particles with an overall neutral charge. • The faster they move, the greater the force when they collide causing atoms to rip off.

36. What is the plasma state? • Much of the matter in the universe is plasma, matter made up of positively and negatively charged particles with an overall neutral charge. • The faster they move, the greater the force when they collide causing atoms to rip off. • Ex. Stars, lightning bolts, neon & fluorescent bulbs, and auroras.

37. Thermal Expansion • Thermal expansion is an increase in the size of a substance when the temperature is increased. • The kinetic theory explains both thermal expansion and contraction that occurs in most solids, liquids and gases.

38. How does expansion occur in solids? • Expansion joints prevent concrete cracks when temperatures change.

39. How does expansion occur in liquids? • One example of this occurs in a thermometer. • The addition of energy makes particles in the liquid move farther apart.

40. How does expansion occur in gases? • An example is a hot air balloon. Heating the air makes it expand and decreases the density making the balloon rise.

41. Why does water behave in different ways? • Water expands when it freezes due to the negative and positive charges on it.

42. Why does water behave in different ways? • Water expands when it freezes due to the negative and positive charges on it. • Unlike charges attract each other. As the temp drops, the water particles move closer together lining up so that positive and negative areas are near each other leaving empty spaces in the structure.

43. Why does water behave in different ways? • Water expands when it freezes due to the negative and positive charges on it. • Unlike charges attract each other. As the temp drops, the water particles move closer together lining up so that positive and negative areas are near each other leaving empty spaces in the structure. • Solid ice is less dense than liquid water.

44. Solid or Liquid? • Not all materials have a definite temperature when they change from solid to liquid. • Some get softer and slowly turn to liquid over a range of temperatures.

45. Solid or Liquid? • Not all materials have a definite temperature when they change from solid to liquid. • Some get softer and slowly turn to liquid over a range of temperatures. • These amorphous solids, like glass & plastic, do not have the ordered structure of crystals.

46. Solid or a Liquid? • Liquid crystals start to flow in the melting phase, but keep their ordered structure. • Liquid crystals respond to temperature changes and electric fields. • LCDs are used in watches and calculators.

47. Solid Liquid Gas Arrangement: Closely packed together Arrangement: Arrangement: Overcome attractions Behavior: Behavior: slip out of arrangement & flow Behavior:

48. Solid Liquid Gas Arrangement: Closely packed together Arrangement: Cling together with definite volume Arrangement: Overcome attractions Behavior: slip out of arrangement & flow Behavior: do not have definite shape or volume Behavior: Energy is needed for them to slip out of arrangement

49. 2 Properties of Fluids • Archimedes’ Principle • Pascal’s Principle • Bernoulli’s Principle

50. How do ships float? • Buoyancy is a fluid’s ability to exert an upward force on an object in it.