Quiz Two (9:30-9:35 AM)
UNIVERSITY OF SOUTH ALABAMA
GY 111: Physical Geology
Lecture 4: Basic Mineral Chemistry
Instructor: Dr. Douglas W. Haywick
Last Time
1. Introduction to rocks
2. The Rock Cycle
Rocks
Rocks are naturally occurring solids containing one or
more minerals.
e.g., Granite
Rocks
We recognize 3 major rock groups:
1) Igneous (“born of fire”); originally
molten
2) Sedimentary; originally particulate
material or produced from
precipitation out of water
3) Metamorphic; pre-existing rocks
modified by pressure or temperature
Igneous Rocks
Can be either extrusive (volcanic) or intrusive (plutonic):
Extrusive (volcanic) rocks
can be erupted as lava…
Sedimentary Rocks
We recognize 4 major classes of sedimentary rocks:
1) Siliciclastic: composed of broken bits of silicate minerals
2) Biochemical: mostly composed of the remains of calcium
carbonate-secreting beasties
3) Chemical; formed through chemical precipitation alteration
4) Organic; formed from plant material
Peat bog
Metamorphic Rocks
We recognize 3 divisions of metamorphic rocks:
1) Foliated; display a prominent layering
2) Non-foliated; do not display layering
3) Cataclastic; composed of broken up bits of rock
mylonite
The Rock Cycle
The Rock Cycle
The Rock Cycle
Igneous
Loop
Metamorphic
Loop
Sedimentary
Loop
Today’s Agenda
1. Elementary Chemistry (atomic structure)
2. Isotopes
3. The Periodic Table
4. Bonding
Web notes 4:
Why Chemistry in GY 111…
Why Chemistry in GY 111…
Math
Physics
Geology
Chemisty
Biology
Why Chemistry in GY 111…
Math
Physics
Geology
Geochemistry
Chemisty
Biology
Fluorite: CaF2
Copper: Cu
Calcite: CaCO3
Source: csm.jmu.edu
Fluorite: CaF2
Copper: Cu
Calcite: CaCO3
Source: csm.jmu.edu
Basic Chemistry
•Geologists need to understand chemistry because minerals
(and the rocks that contain them) are chemical compounds
Basic Chemistry
•The origins of chemistry go way back to prehistoric times
Basic Chemistry
•The origins of chemistry go way back to prehistoric times
•Alchemists identified 4 “elements” (basic building blocks of
everything)
1) Fire
2) Water
3) Earth
4) Air
Basic Chemistry
•The origins of chemistry go way back to prehistoric times
•Alchemists identified 4 “elements” (basic building blocks of
everything)
1) Fire
A worthwhile quest,
2) Water
but completely wrong
3) Earth
4) Air
Basic Chemistry
Halite
NaCl
Basic Chemistry
Halite
NaCl
Basic Chemistry
Halite
NaCl
Basic Chemistry
Halite
NaCl
Basic Chemistry
Halite
NaCl
Basic Chemistry
Halite
NaCl
Basic Chemistry
Halite
NaCl
0.0000000001 m
Atoms & Atomic Particles
Na
Cl
• The sodium-chlorine pairing is called a molecule
Atoms & Atomic Particles
Na
Cl
• The sodium-chlorine pairing is called a molecule
• Molecules are composed of uncharged atoms and/or
charged atoms (ions)
Atoms & Atomic Particles
Na
Cl
• The sodium-chlorine pairing is called a molecule
• Molecules are composed of uncharged atoms and/or
charged atoms (ions)
• An atom is the smallest component of an element that
can retain the properties of that element
Atoms & Atomic Particles
• Atoms are composed of 3 fundamental particles:
1) Protons 2) Neutrons 3)Electrons
Atoms & Atomic Particles
• Atoms are composed of 3 fundamental particles:
1) Protons 2) Neutrons 3)Electrons
• Protons & Neutrons always reside in the center of the atom
termed the nucleus
Nucleus (Protons + Neutrons)
Atoms & Atomic Particles
• Atoms are composed of 3 fundamental particles:
1) Protons 2) Neutrons 3)Electrons
• Protons & Neutrons always reside in the center of the atom
termed the nucleus
• Electrons are always located in the electron cloud in complex
orbitals where they “orbit” the nucleus
Electron Cloud (Electrons)
Nucleus (Protons + Neutrons)
Atoms & Atomic Particles
• Proton: has a mass of 1 and a positive charge (+)
• Neutron: has a mass of 1 and a neutral charge (o)
• Electron: has a mass of 0 and a negative charge (-)
Atoms & Atomic Particles
• Proton: has a mass of 1 and a positive charge
• Neutron: has a mass of 1 and a neutral charge
• Electron: has a mass of 0 and a negative charge
This is not entirely correct (at
least as far as mass is concerned)
Atoms & Atomic Particles
• Proton: has a mass of 1 and a positive charge
• Neutron: has a mass of 1 and a neutral charge
• Electron: has a mass of 0 and a negative charge
• The number of protons and neutrons in the nucleus is variable
and defines the different chemical elements (refer to the
periodic table)
Atoms & Atomic Particles
• Proton: has a mass of 1 and a positive charge
• Neutron: has a mass of 1 and a neutral charge
• Electron: has a mass of 0 and a negative charge
• The number of protons and neutrons in the nucleus is variable
and defines the different chemical elements (refer to the
periodic table)
• For an uncharged atom:
# of protons = # of electrons
Atoms & Atomic Particles
Hydrogen:
1 proton,
1 electron
Atoms & Atomic Particles
Helium:
2 protons,
2 neutrons,
2 electrons
Atoms & Atomic Particles
Carbon:
6 protons
6 neutrons
6 electrons
Atomic Number & Weight
• Atomic Number: the sum of the protons in the atom; The
number uniquely identifies the element.
Hydrogen = 1
Helium = 2
Carbon = 6
Atomic Number & Weight
• Atomic Number: the sum of the protons in the atom; The
number uniquely identifies the element.
• Atomic Weight: the sum of the protons and neutrons in the
nucleus of the atom
Hydrogen = 1
Helium = 4
Carbon = 12
Atomic Number & Weight
• By convention, we put both numbers on a letter that
symbolizes that particular element:
1H1
2He4
6C12
Atomic Number & Weight
• By convention, we put both numbers on a letter that
symbolizes that particular element:
1H1
2He4
Atomic
Number
Atomic
Weight
6C12
Isotopes
• The number of protons and electrons for an element does
not vary, but the number of neutrons can.
Isotopes
• The number of protons and electrons for an element does
not vary, but the number of neutrons can. e.g., hydrogen
+
-
1H1
Proton
Neutron
-
Electron
Isotopes
• The number of protons and electrons for an element does
not vary, but the number of neutrons can. e.g., hydrogen
+
-
-
1H1
1H2
Proton
Neutron
-
Electron
Isotopes
• The number of protons and electrons for an element does
not vary, but the number of neutrons can. e.g., hydrogen
+
-
-
-
1H1
1H2
1H3
Proton
Neutron
-
Electron
Isotopes
• The number of protons and electrons for an element does
not vary, but the number of neutrons can. e.g., hydrogen
+
-
-
-
1H1
1H2
1H3
Stable
Unstable
Ions
Ions
• When an atom in its elemental state receives or gives up
one or more electrons it is then termed an “ion”
Ions
• When an atom in its elemental state receives or gives up
one or more electrons it is then termed an “Ion”
• Positively charged ions are cations
Ions
• When an atom in its elemental state receives or gives up
one or more electrons it is then termed an “Ion”
• Positively charged ions are cations
• Negatively charged ions are anions
Ions
• When an atom in its elemental state receives or gives up
one or more electrons it is then termed an “Ion”
• Positively charged ions are cations
• Negatively charged ions are anions
• The ability to give up or take on electrons in an atom is
dependent on the atomic number (i.e. the number of
electrons in the electron shells)
Simple atomic structure:
Simple atomic structure:
The Bohr atomic model
Source:http://www.amptek.com/xrf_3.gif
Simple atomic structure:
Source:http://www.amptek.com/xrf_3.gif
Level
(n)
"Name"
# of electrons
(2n2)
1
K
2
2
L
8
3
M
18
4
N
32
5
O
50
The Periodic Table
The Periodic Table
1 electron in outer shell
The Periodic Table
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
3 Es in outer shell
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
4 Es in outer shell
3 Es in outer shell
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
5 Es in outer shell
4 Es in outer shell
3 Es in outer shell
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
6 Es in outer shell
5 Es in outer shell
4 Es in outer shell
3 Es in outer shell
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
7 Es in outer shell
6 Es in outer shell
5 Es in outer shell
4 Es in outer shell
3 Es in outer shell
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
8 electronss in outer shell
7 Es in outer shell
6 Es in outer shell
5 Es in outer shell
4 Es in outer shell
3 Es in outer shell
2 electrons in outer shell
1 electron in outer shell
The Periodic Table
Chemical Bonding
Chemical Bonding
 Occurs through the action of the electrons in the
outer shells of atoms.
Chemical Bonding
 Occurs through the action of the electrons in the
outer shells of atoms.
 Partially filled shells are less stable (higher energy)
than filled shells (lower energy)
Chemical Bonding
 Occurs through the action of the electrons in the
outer shells of atoms
 Partially filled shells are less stable (higher energy)
than filled shells (lower energy)
Level
(n)
"Name"
# of electrons
(2n2)
1
K
2
2
L
8
3
M
18
4
N
32
5
O
50
Chemical Bonding
 Occurs through the action of the electrons in the
outer shells of atoms.
 Partially filled shells are less stable (higher energy)
than filled shells (lower energy)
 Chemical reactions
forming molecules
strive to fill shells in
atoms
Level
(n)
"Name"
# of electrons
(2n2)
1
K
2
2
L
8
3
M
18
4
N
32
5
O
50
Already have filled shells
Gain 1 electron
Gain 2 electrons
Gain 3 electrons
Loose/gain 4 Es
Loose 3 electrons
Loose 2 electrons
Loose 1 electron
Chemical Bonding
Chemical Bonding
Chemical Bonding
Three Major types:
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms
to form ions
Na
Cl
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms
to form ions
Na
Cl
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms
to form ions
Na+
Cl-
Ionic Radius
Source:http://intro.chem.okstate.edu
Determines the length of chemical bonds
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms to
form ions
2) Covalent bonding: sharing of electrons between atoms
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms to
form ions
2) Covalent bonding: sharing of electrons between atoms
-
-
-
-
-
-
-
-
Cl
-
-
Cl
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms to
form ions
2) Covalent bonding: sharing of electrons between atoms
-
-
-
-
-
-
-
-
-
Cl2
-
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms to
form ions
2) Covalent bonding: sharing of electrons between atoms
-
-
-
-
-
-
-
-
-
Cl2
-
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms to
form ions
2) Covalent bonding: sharing of electrons between atoms
3) Metallic bonding: freely exchangeable electrons
between nuclei
Chemical Bonding
Three Major types:
1) Ionic bonding; exchange of electrons between atoms to
form ions
2) Covalent bonding: sharing of electrons between atoms
3) Metallic bonding: freely exchangeable electrons
between nuclei
Chemical Bonding
One Minor type:
1) Hydrogen Bonding (Van der Waals): weak attraction
between ions of opposite charge
Chemical Bonding
One Minor type:
1) Hydrogen Bonding (Van der Waals): weak attraction
between ions of opposite charge
Bonding (Properties)
Bond
Mineral properties
Ionic
-strong bond
-high melting points
-vitreous lusters
-higher solubility
Covalent
- strong bonds
- hard minerals
- very high melting points
- vitreous – adamantine lusters
Metallic
- weak bonds
- low to high melting points
- metallic lusters
-electrically conductive
Today’s Homework
1. Download and read web notes 4
2. Study your minerals in GY 111L
Next Time
Crystal chemistry and mineral classes
(web notes 5)
GY 111: Physical Geology
Lecture 4: Basic Mineral Chemistry
Instructor: Dr. Doug Haywick
dhaywick@southalabama.edu
This is a free open access lecture, but not for commercial purposes.
For personal use only.