Phases of Matter

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Phases of Matter

• Four States
• Solid, Liquid, Gas, Plasma

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Matter (next unit)

• Phases of Matter
• Solids
• Has definite shape and definite volume
• Does not take the shape of the container and does
  not take the volume of the container
• Atoms or molecules are well ordered into a
  crystalline lattice for most materials
• Exceptions are things like glass which is really
  a very slow flowing liquid

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Matter

• Liquids
• No definite shape and has a definite volume
• Takes the shape of container and does not take
  the volume of the container
• Pretty incompressible
• Atoms or molecules loosely bonded to neighbors,
  but in close proximity
• Allows fluid to flow

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Matter

• Gasses
• No definite shape and no definite volume
• Take the shape of the container and takes the
  volume of the container
• Compressible
• Atoms or molecules are widely separated and have
  little interaction with each other aside from
  elastic collisions

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Matter
6
Matter
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Matter

• Solids are incompressible
• Gases are compressible
• Liquids are very slightly compressible usually
  considered incompressible

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Matter

• Which of the following does not describe the
  solid state?
• a. Rigid, fixed, constant shape
• b. Constant volume
• c. Easily compressed
• d. Particles vibrate in fixed position
• e. All describe the solid state

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Matter

• Which of the following does not describe the
  liquid state?
• a. Particles vibrate in fixed position
• b. Same shape as the bottom of the container
• c. Constant volume
• d. Pourable
• e. All describe the liquid state

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Matter

• Which of the following does not describe the
  gaseous state?
• a. Same shape as a closed container
• b. Same volume as a closed container
• c. Random, independent particle movement
• d. Easily compressed
• e. All describe the gaseous state

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Matter

• Plasma
• Temperature is so high that outer electrons are
  separated from their underlying atoms
• No molecules exist
• What is a molecule
• Molecule - neutral group of atoms united by
  covalent bonds
• Covalent bond - chemical bond resulting from the
  sharing of electrons between two bonding atoms
• Particles are electrically charged
• Sun, stars, inside a fluorescent bulb

12
Matter

• Mass
• Matter - anything that has mass and occupies
  space
• Mass - measure of the quantity of matter
• Weight is different.
• Weight is the force of gravity on the quantity of
  matter
• Weight changes with location moon vs. earth
• Varieties of matter
• Characteristics
• Pure sample pure sample of the same
• Substance - matter which has the same
  characteristics or properties

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Matter

• Element
• Can not be broken down into other substances by
  ordinary chemical means
• Periodic table of elements
• 91 elements found in nature
• The rest synthesized in a lab
• Compounds
• Substance made of two or more elements chemically
  combined
• Compounds can be decomposed into simpler
  substances
• Combined in definite proportion by mass
• The chemical and physical properties are
  different from those of its constituents

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Matter

• Compounds can be formed from simpler substances
  by chemical change, and they can be decomposed
  into simpler substances by chemical change
• Math problems
• In every 100 g sample sample of water 11.2 g is
  hydrogen and 88.8 g is oxygen. How many grams of
  hydrogen is in a 140.0 g sample of water?
• Sucrose (table sugar) is 42.1 carbon ( C ), 6.4
  hydrogen (H), and 51.5 oxygen. How many grams
  of C do you consume when you eat 50 g of sugar?

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Matter

• Mixtures
• Consists of two or more substances, each which
  retains its individual properties
• Does it separate into 2 or more layers?
• Does it have to separate into 2 or more layers?
• Examples
• Element with element
• A compound is mixed with one or more compound(s)
• One or more element(s) with one or more
  compound(s)
• Characteristics
• Mixture retains properties of constituents
• Homogeneous mixture - prefix homo same
• Heterogeneous mixture - prefix hetero different

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Matter

• Physical and Chemical Properties
• Physical - Characteristics that can be observed
  w/o production of a new substance
• Color
• Odor
• Taste
• Hardness
• Density
• Melting point (MP) and Boiling point (BP)
• Metals special characteristics
• Malleable- hammered into sheets
• Ductile drawn into wires
• Luster shine of metal

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Matter

• Chemical- interaction with other substances to
  produce new substances
• Iron rust
• Nitrogen does not interact w/ most things as a
  gas
• Physical and Chemical Change
• Physical change one or more physical properties
  of a substance are changed w/o change in the
  substances chemical properties or composition

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Matter

• Chemical change change that results in the
  production of one or more substances that differ
  in chemical properties and composition from the
  original substance
• Change in energy every change in matter
  involves an energy change
• Physical energy change is not as noticeable
• crystallization, freezing high energy release
• melting, evaporation low energy
• Chemical energy change more noticible
• explosions, burning high energy
• formation of hydrogen gas, oxygen gaslow energy

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Energy and Phase Change
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MatterEnergy and Phase Change
Adding heat at a constant rate
T
Time
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Matter
Energy and Phase Change
Adding heat at a constant rate
T
Boiling
Melting
Time
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Matter

• Conservation of mass
• Law of conservation of mass
• Matter can not be created or destroyed
• For ordinary chem change this holds true
• Lavoisier closed container no change,
  open container change
• Relative abundance
• Free state/Elemental state elements alone or
  uncombined
• Combined state elements combined w/ other
  elements (most elements occur in nature only in
  combined state)
• Symbols of the elements chemistry reference
  table pg. 11-12

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Matter

• States of matter
• For a given substance, all four states are
  possible
• Increase temperature and a PHASE CHANGE occurs
• Solid gt Liquid gt Gas gt Plasma

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Matter

• Phase changes
• Evaporation
• Condensation
• Boiling
• Melting
• Freezing

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Water Molecule

• Two Hydrogen Atoms, One Oxygen Atom

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Evaporation
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Matter

• Evaporation
• Liquid cools because it loses higher energy
  molecules or atoms
• Air cools because the molecules leaving give up a
  lot of energy to break free, so they have much
  lower energy after they gain their freedom
• Solid gt Gas directly is sublimation

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Condensation
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Condensation

• Condensation
• The opposite of evaporation
• Evaporation and Condensation are a SURFACE
  phenomenon
• Interaction of molecules at the liquid-air
  interface

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Boiling

• Molecules break free of the liquid bonds and form
  little bubbles
• If the vapor pressure in the bubble is large
  enough to resist the pressure of the liquid, and
  the air pressure above the interface they rise
  and escape to the outside
• Remember, liquid is cooling and air is cooling

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Boiling
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Boiling
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Melting and Freezing

• Change between liquid and solid
• Bonds between molecules break when solid melts
• Takes energy to break the bonds
• Freezing is the opposite of melting
• Molecules move slowly enough that bonds can form

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Melting and Freezing

• Why does salt melt ice?

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Energy and Phase Change
For Pure Water
334 joules/gram
2256 joules/gram
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Boiling Potatoes

• So, when you want garlic mashed potatoes and you
  take potatoes and cut them up and put them in
  boiling water, do they cook faster when the water
  is really bubbling compared to when the water is
  just barely bubbling???

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Boiling Potatoes