MINERALS g110 lecture prepared by bob hall revised 7302000

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MINERALSg110 lecture prepared by bob
hallrevised 7/30/2000
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Topics to Be Covered on Minerals

• Chemical organization of matter
• Atoms, isotopes, ions
• Molecules
• Elemental minerals
• Chemical bonding
• Internal structure
• Silicate minerals

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Chemical Organizationof Matterinto Minerals

• 1. Atoms, Isotopes, and Ions
• 2. Molecules

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What is an atom?

• 1) Is it alive? No, never has
  been.
• 2) Can I see one? No, not really.
• 3) So, cant smell it
• feel it or even see it,
• yet we make bombs with it.
• Used to. Not with one atom, of course.
• 4) Where can I get one? At the bookstore?
• You already have all you need.

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Models of Simple Atoms
Hydrogen
Helium
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An Atomic Cloud(of a different sort)

• Protons (pro gung ho, very positive, but fat)
• Neutrons (neutered wimp not involved, but
  fat)
• Electrons (electricity energy get something
  done and stay skinny)
• So, who do you think is zipping around the
  neighborhood
• And who is just sitting there watching?

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Energy-level shells
1st 2nd 3rd
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Keeping Things Hanging in Balance

• Electrons negative, protons positive, neutrons
  dont care. To be happy, atoms must have overall
  electrical neutrality.
• Now, everbodys wimpy.
• But happy, for happiness is electrical
  neutrality.
• Without this, we do not have an atom.

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Atoms Make Up the Chemical Elements

• Atomic number Number of protons
• Number of electrons too.
• What about neutrons?
• Just wait!
• Atomic mass number of protons plus number of
  neutrons
• What about electrons? Wimps.

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Lets work a problem. Say what?
E ELECTRON

• What is the atomic number of this element?
• What is the atomic mass of this element?
• Am I too fat? Do I need to reduce my atomic
  (m)ass?
• Sometimes you can do that. But youll still be
  fat.

N NEUTRON P PROTON
E
E
3P
3N
E
Is this the wheel of fortune? Wheres Vanna?
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Isotope, What is it, really?

• Almost a household word, but can you tell me what
  it actually is?
• Some new mouthwash?
• No, look at the atom again. What can vary in
  number?
• I dont know.
• Neutrons, because they wont disrupt electrical
  neutrality. You may be a slow learner.

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More stuff on isotopes

• Quiz time fill-in-the-blank
• All isotopes of a given chemical element have the
  same number of_____________

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What is an ion?One of those crossword puzzle
words?

• Lets change an atom into an ion.
• Is that an elect(tron) change operation?
• Lucky guess.
• Anion a gain of one or more electrons
• Cation a loss of one or more electrons
• But, are we still happy?
• I am.

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Are there elemental minerals?(those minerals
containing only one chemical element)
Some interesting minerals here.
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MoleculesI know what a mole is, but what is a
cule?

• Happiness is a cation electrically balanced by
  receipt of an anions electron.
• Neutrality once again.
• Chemical compound combination of ions of more
  than one element
• So, how do we do that?

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Ionic Bonding

• Transfer of Electrons
• Example
• Formation of sodium chloride ?
• Na Cl-
• NaCl
• Now we have formed the minerals internal
  structure.

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Sodium Chloride(ionic bonding)
Sodium (Na)
Chlorine (Cl)
Fig. 2.5 in text
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Internal Structure of Halite (NaCl)
Red Cl Blue Na c
Cubic structure
Fig. 2.9
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Covalent Bonding

• Electron Sharing
• This will be more fun, wont it?
• Example water
• The electron of each H
• shared with the O-2
• Metallic bond electron wandering
• I would say it is electron promiscuity.

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Covalent Bonding
Shared electrons
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In Control Internal Structure and Chemical
Composition

• Fundamental to definition of mineral.
• Can be determined in several ways, well by
  X-ray Diffraction
• Influences chemical composition and physical
  properties.
• Provides part of the basis for classification of
  minerals.

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Stop, Stop, StopYou forgot something.

• Oh, yes, the Silicates

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Silicates

• I have a good idea.
• That is very dangerous.
• Lets have the students study about silicates on
  their own.
• That is a good idea. Well give them a quiz.
• Things to know about the silicates 1) their
  importance, 2) their internal structures, 3)their
  properties, their occurrence.

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Silicon-Oxygen Tetrahedron
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Silicate Structures
Single Chain Double Chain Sheet
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Single Tetrahedra
Involve single tetrahedra held together by
cations.
Example garnet
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Single Tetrahedra
Garnet
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Single-Chain SilicatesDouble-Chain Silicates
Single chain Double
chain Augite
Hornblend
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Sheet Silicates
Muscovite
Biotite
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Framework
Quartz
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Terms used in G110 for study of Minerals

• Technical Terms
• Atom Proton
• Cation Neutron
• Anion At. No.
• Isotope At. Mass
• Internal
• Electron structure
• Covalent Ionic
• Bonding bonding
• Metallic bond
• Mineral groups
• Silicates

• Familiar Terms
• Element
• Nucleus
• Chemical compound
• Molecule

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Student Responsibilities onMinerals -1

• What you need to know
• Explain the structure of the atom and all its
  components.
• What are the properties or characteristics of an
  atom? An ion? an isotope? A different kind of
  ion? How do they differ from each other?
• Understand the concept of atomic number and
  atomic mass. Also, be able to work diagram
  problems that ask for atomic number, atomic mass,
  how to recognize an odd ball isotope, etc.

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Student Responsibilities onMinerals -2

• What are the types of chemical bonds? How does
  each work? How does each type of bond influence
  the properties of our minerals?
• What are the native metals?
• How are the following inter-related?
• a minerals composition
• a minerals internal structure
• a minerals physical properties
• Know as much as possible about the silicate
  minerals.