Physical Science

1
Physical Science

• Ch. 16

2
Kinetic Theory

• Explanation of how particles
• in matter behave
• All matter is composed of small particles (atoms,
  molecules, and ions)
• These particles are in constant, random motion
• These particles are colliding with each other and
  the walls of their container

3

• Temperature
• Explains how hot or cold an object is.
• Thermal Energy
• The total energy of a materials particles
• Kinetic
• vibrations movements
• Potential
• based on position

4
States of Matter

• Solid
• Closely packed together
• Liquid
• More energy, particles able to move around each
  other
• Gas
• Lots of energy, able to overcome the attraction
  between other particles
• Plasma
• Contains positively and negatively charged
  particles

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State of Matter Definite Shape Definite Volume
Solid YES YES
Liquid NO YES
Gas NO NO
6
Phase Changes

• Melting
• Going from Solid to Liquid
• Freezing
• Going from Liquid to Solid
• Vaporization
• Going from Liquid to Gas
• Condensation
• Going from Gas to Liquid
• Sublimation
• Going from Solid to Gas

7
Solids to Liquids

• Melting point
• Temperature at which a solid begins to liquefy
• Heat of fusion (Hf)
• Amount of energy required to change a substance
  from a solid to a liquid

8
Liquids to Solids

• Freezing point
• Temperature at which a liquid begins to solidify
• Heat of fusion (Hf)
• Amount of energy required to change a substance
  from a liquid to a solid

9
Liquid to Gas

• Vaporization point
• Temperature at which a liquid begins to vaporize
• Heat of vaporization (Hv)
• Amount of energy required to change a substance
  from a liquid to a gas

10
Gas to Liquid

• Condensation point
• Temperature at which a gas begins to condensate
• Heat of vaporization (Hv)
• Amount of energy required to change a substance
  from a gas to a liquid

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Critical Points

• Heat of Fusion
• Same for both melting and freezing for a
  substance
• Heat of Vaporization
• Same for both vaporization and condensation

12
Critical Temperatures

• A substance will melt and freeze at the same
  temperature.
• A substance will vaporize and condensate at the
  same temperature.

13

• Boiling Point
• Temperature at which pressure of the vapor in the
  liquid is equal to the external pressure acting
  on the surface of the liquid
• Diffusion
• Spreading of particles through out a given volume
  (container) until they are evenly spread out

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15
Thermal Expansion

• The increase in size of a substance when the
  temperature is increased.
• When temperature increases an object expands
• When temperature decreases an object contracts

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• Crystalline Solids (ex. Salt)
• High ordered structures
• Made up of several crystals
• Amorphous Solids (ex. Candle)
• Lack of ordered within structure
• Without form
• Liquid Crystals (ex. LCD)
• Retain geometric order in specific dimensions
• Highly sensitive to temperature changes and
  electric fields

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Section 2
Properties of Fluids
18

• Buoyancy
• The ability of a fluid to exert an upward force
  on an object immerse in it.
• Archimedes Principle
• The buoyant force on an object is equal to the
  weight of fluid displaced by the object.

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Pascals Principle

• The pressure applied to a fluid is transmitted
  throughout the fluid.
• The pressure will remain the same in all of the
  fluid
• F1 F2
• A1 A2

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• Viscosity
• Resistance to flow by a fluid
• Oil vs. water
• Oil has greater viscosity or greater resistance
  to flow
• Rise in temperature lowers the viscosity of a
  substance

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• Density
• Mass per unit of volume
• D Mass
• volume
• Pressure measured in pascals (Pa)
• Force exerted per unit area
• P Force
• Area

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• Fluid
• Liquid or a gas
• Bernoullis Principle
• When the velocity of a fluid increases, the
  pressure exerted by the fluid decreases
• Fluids flow faster when forced to flow through
  narrow spaces

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Relating to Life

• Principle Use
• Archimedes Ships
• Why we can float
• Pascal's Hydraulics
• Why we can use jacks/lifts
• Bernoullis - Flying
• Driving between 2 semis
• Blowing on a paper

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Section 3
Behavior of Gases
25
Boyles Law (temp constant)

• A decrease in the volume of gas will result in an
  increase in pressure
• An increase in the volume of gas will result in
  a decrease in pressure
• V1P1 V2P2

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V120 P1 30P2 120

• V1 P1 V2 P2
• (20)(30) (V2)(120)
• 600 (V2)(120)
• 5 V2

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V150 P1 30V2 120

• V1 P1 V2 P2
• (50)(30) (120)(P2)
• 1500 (120) (P2)
• 12.5 P2

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Charless Law(pressure constant)

• Volume of a gas increases with increasing
  temperature
• Volume of a gas decreases with decreasing
  temperature
• V1 V2
• T1 T2

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V120, T1 30, T2 120

• V1 V2
• T1 T2
• 20 V2
• 30 120
• 2/3 120 V2
• 80 V2
  gt

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V120, T1 30, T2 120

• V1 V2
• T1 T2
• 20 V2
• 30 120
• 120 20 V2 30
• 2400 V2 30
• 80 V2

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V1120, T1 30, V2 300

• V1 V2
• T1 T2
• 120 300
• 30 T2
• 120 T2 300 30
• 120 T2 9000
• T2 75

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V1120, T1 30, V2 300

• V1 V2
• T1 T2
• 120 300
• 30 T2
• 4 300
• T2
• 4 T2 300
• T2 75

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Relating to Life

• Principle Use
• Boyles (temperature constant)
• Squeezing a balloon
• Charles (pressure constant)
• Why balloons decrease in size when kept in a cold
  room
• Reason for statement on hair spray keep away
  from heat, contents under pressure

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Problems
Boyles Law
V1 V2 P1 P2
1 30 15 ? 7
2 40 15 3 ?
3 ? 20 30 60
4 10 ? 34 102
Charles Law
V1 V2 T1 T2
5 38 138 ? 69
6 ? 15 20 45
7 30 ? 6 13
8 76 17 38 ?
35
Answers
Boyles Law
V1 V2 P1 P2
1 30 15 3.5 7
2 40 15 3 8
3 40 20 30 60
4 10 2.35 34 102
Charles Law
V1 V2 T1 T2
5 38 138 19 69
6 6.67 15 20 45
7 30 65 6 13
8 76 17 38 8.5