Chapter 2 Section 2 Notes

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Chapter 2 Section 2 Notes

• Matter and Energy

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Kinetic Theory of Matter

• Useful for seeing differences in the 3 common
  states of matter on earth solid, liquid, and
  gas.

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Kinetic Theory of Matter3 Main Points

1. All matter is made of atoms and molecules which
   act like tiny particles that are always in
   motion.
2. The higher the temperature, the faster the
   particles move.
3. At the same temperature, heavier particles move
   slower than lighter particles.

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States of Matter

• Solid particles are in a fixed position
• rigid structure no freedom to change positions
• Particles are held closely together by strong
  attractions
• Diagram

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Liquid

• Liquid particles are closely packed, but can
  still slide past each other
• Take the shape of their container
• Particles are close but not as close as a solid
• Particles can move randomly and spread on their
  own
• Diagram

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Viscosity

• Viscosity resistance of a fluid to flow
• syrup is more viscous than water
• Determined by the attraction of particles the
  stronger the attraction, the more viscous (thick)
  the liquid is.

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Gas

• Gas particles are in a constant state of motion
  and rarely stick together
• expand to fill available spaces
• Example scents of food or perfume
• Diagram

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Gas

• A balloon filled with helium is under pressure
  Pressure force exerted per unit area of a
  substance
• If there is too much pressure (too many helium
  particles) in a balloon, what happens?
• A gas under pressure will escape the container if
  possible. Think about an air filled balloon that
  you let go.

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Kinetic Theory

• Using the Kinetic Theory of matter, explain why a
  balloon filled with helium goes flat faster than
  one filled with regular air.

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Fluids

• Fluids substances that can spread
• Both liquids and gases can spread, so they are
  considered fluids.

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Plasma

• Plasma most common state of matter in universe
  NOT on Earth
• Makes up 99.9 of the universe
• Plasma is superheated gas and is a collection of
  free moving electrons and ions the term came
  about in 1920s to represent electrically charged
  particles at high energy

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Plasma

• Examples of plasma on earth
• lightning
• fire

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Energy

• Energy the ability to change or move matter
• Examples of energy or sources of energy
• heat, light, spring coiling, batteries
• Energy must be ADDED to melt or evaporate
  substances
• Aluminum must be melted before it can be recycled
• As aluminum particles gain heat, particles move
  faster and break away from fixed positions and
  become liquids called melting

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Energy

• Energy must be RELEASED to make a gas become a
  liquid or solid again.
• When H2O is a gas and molecules slow down the
  water vapor returns to a liquid (called
  condensation). When molecules slow down even
  more, the water goes to a solid (ice).

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Energy

• Energy relationship between solid, liquid, and
  gas diagram

liquid
gas
solid
Energy ABSORBED
Energy RELEASED
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Important Note

• Changing the state of matter does NOT change the
  substance or mass.
• Water, steam, and ice are all H2O the only
  change is the nature of attraction between
  molecules

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Phase Change Diagram

Solid
Melting
Sublimation
Deposition
Freezing
Condensation
Liquid
Gas
Evaporation
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Phase Changes

• Evaporation change of a substance from a liquid
  to a gas.
• Condensation change of a substance from a gas to
  a liquid.
• Sublimation change of a substance from a solid
  to a gas.
• Deposition change of a substance from a gas to a
  solid
• Example Water vapor without becoming liquid-
  this is how snow forms in clouds.

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Law of Conservation of Mass

• Law of Conservation of Mass Mass cannot be
  created or destroyed
• Example Burning a match consider what you
  start and end with.

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Trivia Question

• Trivia Question If mass cannot be created or
  destroyed, then why do we have to replace our
  tires when the rubber wears away?

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Law of Conservation of Energy

• Law of Conservation of Energy Energy cannot be
  created or destroyed
• Energy can be converted from one form to
  another.
• Example A wristwatch from chemical energy to
  mechanical energy.