1. STATES OF MATTER

2. First, a few important things:
Arrangement and movement of particles in matter determines the phase
There are FORCES OF ATTRACTION between these particles that determine properties like shape that help distinguish between different phases

3. Describing the States of Matter
Materials can be classified as solids, liquids, or gases based on whether their:
Shapes and volumes are definite (does not change) or
Variable (does change).

5. Shape & Volume
Some materials have a definite shape and volume, some do not.
SHAPE and VOLUME are clues to how the particles within a material are arranged

6. SOLID
LIQUID
GAS

9. Solids
Solid: the state of matter in which materials have a definite shape and a definite volume.
definite means shape and volume will NOT change if you move it from a desk drawer to a backpack
definite does NOT mean that the shape or volume can never change
For example: change shape of pencil when you sharpen it

10. Solids Example: Copper wire Arrangement of atoms:
atoms are packed close together
arranged in an regular pattern (almost all solids have some type of orderly arrangement of particles) page 69, fig.2

12. Liquids
Liquid: the state of matter in which a material has a definite volume and a variable shape.
A liquid always has the same shape as its container and can be poured from one container to another

13. Liquids Example: mercury is a liquid at room temperature
Arrangement of atoms
atoms are close together
Arrangement more random than that of a solid (page 69, fig. 3)

15. Gases
Gases: the state of matter in which a material has neither a definite shape nor a definite volume
As gas takes the shape and volume of its container

16. Gases
Example: air (mixture of gases), natural gas (used for heating), helium (gas found in balloons)
Arrangement of atoms:
atoms have more space between them than in solid/liquid form
Not arranged in a regular pattern (very random, free to move)

18. Other States of Matter
Plasma: found when a gas is heated to a temperature near 10,000 degrees Celsius                                                       
Occurs on Earth mainly in lightening discharges and fluorescent lights
Found most commonly in the universe (Sun and other stars)
TV’s?

22. Other States of Matter
Amorphous Solids: lack the orderly/rigid internal structure found in crystalline solids; "moves" over time
Examples: rubber, asphalt, and glasses

24. Other States of Matter Bose-Einstein condensate (BEC)
Bose and Einstein predicted this state of matter in the 1920’s.
First observed in 1995.
Occurs near absolute zero, 0K
Atoms “clump” together and act as one giant particle.

27. Kinetic Theory
Kinetic Theory: states that all particles of matter are in constant motion
Kinetic Energy: the energy an object has due to its motion
This is why, under ordinary conditions, copper is a solid, mercury a liquid, and helium a gas
Faster an object moves = greater kinetic energy (abbreviated KE)

28. Explaining the Behavior of Gases
Motion in Gases:
There are forces of attraction among the particles in ALL matter.
Particles in a gas are NEVER at rest
Atoms move in a straight line until it collides with another atom or with a wall of the container

29. Explaining the Behavior of Gases
What happens when 2 atoms collide:
One atom may lose KE and slow down
The other atom gains KE and speeds up
TOTAL KE energy of the 2 atoms remains the SAME

30. KINETIC THEORY OF GASES:
The constant motion of particles in a gas allows a gas to fill a container of any shape or size.
Kinetic Theory as applied to gases has 3 main points.

31. KINETIC THEORY OF GASES:
Particles in a gas are in constant, random motion
The motion of one particle is unaffected by the motion of other particles unless the particles collide
Forces of attraction among particles in a gas can be ignored under ordinary conditions
WHAT?!?! WHY?!?! You were just told there were forces of attraction among the particles in ALL matter

32. EXPLAINING THE BEHAVIOR OF LIQUIDS
A liquid takes the shape of its container because the particles in a liquid can flow to new locations. 
The volume of a liquid is constant because the forces of attraction keep the particles together.

33. EXPLAINING THE BEHAVIOR OF LIQUIDS
Tug-of-war between the constant motion of particles and the attractions among particles
Think of trying to walk down the hall between classes
Forces of attraction LIMIT the motion of particles in a liquid, the particles in a liquid CANNOT spread out and fill a container

34. EXPLAINING THE BEHAVIOR OF SOLIDS
Solids have a definite volume and shape because particles in a solid vibrate around fixed locations
Particles in a solid = polite audience in a movie theatre
Movie is running, people stay in their seats
People move within their seat but each person remains in essentially the same location during the movie - they have "FIXED" locations

35. EXPLAINING THE BEHAVIOR OF SOLIDS
Vibration = repetitive back-and-forth motion
Strong attractions among the atoms restrict their motion and keep each atom in a fixed location relative to its neighbors
Each atom vibrates around its location but DOES NOT exchange places with a neighboring atom

36. 3.2 – The Gas Laws

37. Pressure Pressure: the result of a force distributed over an area
The smaller the area of impact is, the greater the pressure produced
Example: walking on a frozen pond (bad ice)
Snow shoes or tennis shoes?
SI unit for pressure is the Pascal (Pa) or N/m2

38. Pressure Objects do not have to be large to exert pressure:
Helium atoms in a balloon are constantly moving
Pressure from a single helium atom is small
But, there are 10^22 helium atoms in a small balloon!!!
That many small collisions will produce noticeable pressure!

39. Pressure
Collisions between particles of gas and the walls of a container cause pressure
More collisions = greater pressure
Speed and mass also affect pressure

40. Factors Affecting Gas Pressure
Factors affecting pressure of gas in a closed container are:
Temperature
Volume
The number of particles in the container

41. Temperature & Gas Pressure
Raising the temperature of a gas will increase its pressure if the volume and the number of particles are constant
Increase Temperature = Increase Pressure T P

42. Temperature & Gas Pressure
Explains why pressure in tires increases after time spent driving...
Constant motion of tires causes air inside to warm up
As temperature rises, KE of the particles increases
Increased KE causes the particles to move faster and collide more with the inner walls of the tires
Increased number of collisions and increased force of impact causes the pressure in the tires to rise

43. Volume & Gas Pressure V P
Reducing the volume of gas increases its pressure if the temperature of the gas and the # of particles are constant Decrease Volume = Increase Pressure V P

44. Breathing…
This relationship shows what happens to the volume and pressure in your lungs when you breathe

45. Inhaling Diaphragm contracts
Contraction causes the chest cavity to expand
Increase in volume causes the air particles to spread out, lowering the pressure inside
Now the pressure of the air outside your body is greater than inside
This causes air to rush into your lungs

46. Exhaling Diaphragm relaxes Volume of chest cavity decreases
Particles of air are squeezed into smaller volume, pressure inside increases
Pressure is greater inside the chest cavity so the air is forced out

47. Particle Number & Pressure
Increasing the number of particles will increase the pressure of a gas if the temperature and volume are constant Increase Particle Number = Increase Pressure P# P

48. Balloon Bursting
This relationship explains why a balloon will burst if you blow too much air into it...
The more particles of air in the same volume will cause more collisions, which increases pressure
Eventually, the rubber cannot withstand the pressure and bursts!

49. Charles’ Law (proportional, same)
Charles' Law states that the volume of a gas is directly proportional to its temperature (Kelvin) if the pressure and the number of particles are constant

50. Charles’ Law

51. Charles’ Law
There is a direct relationship between volume and temperature
If temperature increases, volume increases
The temperature needed to produce a volume of 0 mL = 0 Kelvin = absolute zero = -273 degrees Celsius
Absolute zero has not yet been reached!

52. Charles’ Law

53. Boyle’s Law (inverse, opposite)
Boyle's Law states that the volume of a gas is inversely proportional to its pressure, if the temperature and number of particles are constant

54. Boyle’s Law

55. Boyle’s Law

56. Boyle’s Law
The relationship is opposite for pressure and volume, as one increases, the other decreases!
Example: squeezing a balloon...

57. Boyle’s Law
P1V1 = P2V2

59. Combined Gas Law
Describes the relationship among the temperature, volume and pressure of a gas when the number of particles is constant
It describes the relationship between Charles' Law and Boyle's Law

60. Combined Gas Law

61. 3.3 Phase Changes

62. Phase Change
Phase Change: reversible physical change from one state of matter to another
There are 6 common phase changes:
Melting
Freezing
Vaporization
Condensation
Sublimation
Deposition
Refer to page 85, figure 16 for more detail

63. Phase Changes

64. Phase Changes
During a phase change, the temperature DOES NOT change!!!
During a phase change, energy is transferred between a substance and its surroundings.
Energy is either absorbed or released during a phase change.
Summarize the figure that follows

66. Energy Transfer There are two types of energy transfer: Endothermic
Exothermic

67. Endothermic Endothermic: the system ABSORBS energy from surroundings
Example: melting
The amount of energy absorbed depends on the substance
Heat of Fusion: the amount of energy absorbed
Example: heat of fusion of water as it melts = 334 joules

69. Energy is Conserved Did you know...
As water freezes, it releases 334 joules of energy to its surroundings
As water melts it absorbs 334 joules of energy
The amount of energy absorbed as water melts is the same as the amount of energy released as water freezes: it is CONSERVED!

70. Exothermic Exothermic: system releases energy to its surroundings
Example: Farmers spray water on crops when temperatures are expected to fall below freezing
The freezing of the water releases heat, which helps protect the crop

71. Energy…absorbed or released?

72. Melting
Solid  Liquid
Arrangement of molecules becomes less orderly as a substance melts
Endothermic process

73. Melting
Strong attractive forces in ice keep molecules in fixed positions
When removed from freezer, heat flows from air to ice
Molecules heat up and gain energy = vibrate more quickly
At 0 degrees Celsius some molecules gain enough energy to overcome attractions and break free
When all have enough energy to move, melting is complete

74. Freezing Liquid  Solid
Arrangement of molecules becomes more orderly as a substance freezes
Exothermic

75. Freezing
When liquid is put in a freezer, energy flows from water to air
Kinetic energy of molecules decreases = move slower
Slower movement allows attractive forces to have an effect
When all molecules are orderly, freezing is complete

76. Liquid  Solid Loss in heat melting Gain in heat Liquid Solid
FREEZING
melting
Solid
Gain in heat

77. Vaporization Liquid  Gas
A substance must ABSORB energy in order to change from a liquid to a gas (ENDOTHERMIC)
As a substances vaporizes the particles become less orderly
Heat of Vaporization: one gram of water gains 2,261 joules of energy when it vaporizes
heat of vaporization varies from substance to substance

78. Vaporization Two vaporization processes have been distinguished:
Evaporation
Boiling

79. Evaporation
You go outside after a rain shower on a sunny, warm day you might notice puddles. 
If you return to the same location a few hours later, the puddles are gone.  This shows evaporation.

80. Evaporation
Evaporation: process that changes a substance from a liquid to a gas at temperatures below the substance's boiling point
Molecules near the surface are moving fast enough to escape the liquid and become water vapor
The greater the surface area the faster the water evaporates

81. Vapor Pressure
Vapor Pressure: the pressure caused by the collisions of particles in a vapor with the walls of a container (closed container)
as water evaporates, water vapor collects above the liquid
vapor pressure increases as the temperature increases

82. Vapor Pressure

83. Boiling Particles become less orderly
As you heat water, both the temperature and the vapor pressure of the water increase
Vapor pressure = atmospheric pressure = water boils

85. Boiling Kinetic Theory explains what happens when water boils:
as temperature increases, water molecules move faster and faster
temperature reaches 100 degrees Celsius some molecules below the surface of the liquid have enough KE to overcome the attraction of neighboring particles
boiling point depends on the atmospheric pressure

86. Effect of Pressure On Boiling Point
Lower pressure would lower the boiling point of water.
Water will boil very quickly on the mountain top but the temperature reached is lower than 100oC.
Increasing pressure would raise the boiling point of water.
Water will boil at a higher temperature above 100oC.

87. Normal Boiling Point
Boiling point of a liquid at a pressure of kPa – or standard pressure

88. Condensation Gas  Liquid
During this process particles in a substance become more orderly
Exothermic

89. Condensation
Condensation: the phase change in which a substance changes from a gas or vapor to a liquid
Ever notice after a shower your bathroom mirror has "clouded" over?
This "cloud" on the mirror is caused by water vapor that cooled as it came in contact with the mirror
Process also responsible for the morning dew on the grass

90. Vapor   Liquid Vapor/gas Loss in heat Gain in heat Liquid
CONDENSATION
vaporization
Liquid
Gain in heat

91. Sublimation Solid  Gas
During this process particles become less orderly
Endothermic

92. Sublimation
Sublimation: phase change in which a substance changes from a solid directly to a gas or vapor
Dry Ice (used sometimes in concerts and plays to create a fog-like special effect)
Dry ice is common name for solid form of carbon dioxide
At room temperature it changes from a solid to a gas

93. Sublimation (Dry-Ice)

94. Deposition
Gas  Solid
During this process particles become more orderly
Exothermic

95. Deposition
Deposition: phase change in which a substance changes from a gas directly to a solid
Causes frost to form on windows - water vapor in the air contacts cold glass, the water vapor loses enough KE to change directly from a gas to a solid

96. Gas   Solid Gas Loss in heat sublimation Gain in heat Solid
deposition
SKIPS LIQUID PHASE
sublimation
Solid
Gain in heat