Student PowerPoint for Chapter Goals
Raeva Mulloth and Robert Swift
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Metallic Solids- Extended networks of atoms
held together by metallic bonding
Ionic Solids- Extended networks of ions held
together by ion-ion interactions
Covalent-Network Solids- Extended networks
of atoms held together by covalent bonds
Molecular Solids- Discrete molecules held
together intermolecular forces
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1.
2.
3.
Solids can be divided into three categories on the
basis of how the particles that form the solid
pack.
Crystalline solids are three-dimensional analogs of a
brick wall. They have a regular structure, in which the
particles pack in a repeating pattern from one edge of
the solid to the other.
Amorphous solids have a random structure, with little
if any long-range order.
Polycrystalline solids are combined large numbers of
small crystals or grains in which the structure is regular,
but the crystals or grains are arranged in a random
fashion.
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Ionic
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Molecular
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Low Melting Point, Nonconducting
Metallic
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High Melting Point, Brittle, Hard
Variable Hardness and melting point (depending
upon strength of metallic bonding), Conducting
Network- Covalent
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High Melting Point, Hard, Nonconducting
NaCl-ionic
CO2-molecular
Fahad
Ashraf
Sondra
Lionetti
Helpful
video:
https://ww
w.youtube.c
om/watch?v
=fpPric-r0uo
(3:06)
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Covalent-network solids are held
together by covalent bonds.
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Covalent bonding occurs when pairs
of electrons are shared by atoms.
Atoms will covalently bond with
other atoms in order to gain
more stability, which is gained
by forming a full electron shell.
By sharing their outer most
(valence) electrons, atoms can fill
up their outer electron shell and
gain stability.
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Metals are held together by
metallic bonding
The structure of a metal is
determined by the fact that
each atom tries to be close to
as many other atoms as
possible.
Similar to covalent bonding,
metal atoms share electrons
with neighbors.
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However, metallic atoms share
electrons with many neighboring
atoms, whereas in covalent bonds,
atoms share electrons with few
neighbors.
Composed of positively
charged ions
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Ions are held together by ion-ion interactions.
Ionic bonding is the complete transfer of valence
electron(s) between atoms.
 Like charges repel each other
 Opposite charges attract
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Molecular solids are
solids whose composite
units are molecules.
They are held together
by intermolecular forces.
These include dispersion
forces, dipole-dipole
forces, and hydrogen
bonding.
Intermolecular forces are
much weaker than
chemical bonds.
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Goal 4: Use three dimensional representations
and the interaction of particles to explain the
common macroscopic properties of each class
of solid
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Extended network of atoms
Held together by metallic bonding
Most are malleable and ductile
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Atoms can slip past one another
Primitive, Body-Centered, and Face-Centered
cubic metal structures
2 types of Close Packing
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Hexagonal Close Packing (HCP)-ABA
Cubic Close Packing (CCP)-ABC
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Close-packed atoms, but with different radii and
opposite charges
Primitive Cubic Lattice
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Face-Centered Cubic Lattice
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Cation-center; Anion-lattices on corners
Anions- Lattices on corners
Cations- place depends on coordination numbers
Sizes and Stoichiometry of ions determines structure
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Coordination Numbers
 Size of cation decreases = lower coordination number
 Changes when cations and anions stop touching one another
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If amount of cations and anions aren’t equal then structure
changes
 MgF2
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Have very high meting points. In order to fully
melt, every bond must be broken in the lattice, it is
not enough to separate sheets.
Endless repetitions of an element or molecule in
the x, y , and z direction.
Results in a continuous arrangement of subunits.
 Can take different shapes.
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 Graphite is arranged into layers of hexagons of carbon atoms.
 SiO2 arranged into a constant pattern of Si-O bonds.
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Composed of molecules held together by dipole
forces. Since these bonds are weaker than ionic and
covalent bonds, these compounds are generally
weaker and have lower melting points.
 Examples include ice, sugar, and hydrocarbons.
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Have low densities due to light-weight elements
used in making molecules.
Compounds are not conductive because all
electrons are used in bonding.
By: Maaz Siddiqui and
Shahil Patel
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Most metals have very few electrons in their outermost
energy shells, and some have vacant outer electron
orbitals. What this means for the metal is that its valence
electrons are decentralized and free to move around. In
metal bonds, the electrons wander around and aren't
transferred or shared. It's more of a communal thing
where they belong to all the metal atoms around them.
When metals are next to each other, the valence electrons
don't just stay on their own atom; they roam around the
whole metal complex. They float free as though floating
through a sea of electrons, much like an individual water
molecule floats free in the sea. This is why it is called
the electron sea model.
Each metal atom allows its electrons to roam freely, so
these atoms become positively charged cations. These
cations are kind of like a positively charged island and
are surrounded by a sea of negatively charged electrons.
It looks a bit like this. The attraction between the mobile
electrons and positive centers is a metal bond.
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http://study.com/academy/lesson/metallicbonding-the-electron-sea-model-why-metalsare-good-electrical-conductors.html
https://www.boundless.com/chemistry/textb
ooks/boundless-chemistry-textbook/liquidsand-solids-11/crystals-and-band-theory88/bonding-in-metals-the-electron-sea-model388-3602/
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Goal 6: Describe and alloy and explain how its
structure and properties compare to that of a
pure metallic solid
 Colin and Sam
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Alloys are a type of material that contain more
than one element.
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Alloys are typically metal based
They are mostly man-made for desirable
characteristics.
Some examples include steel, which is made from
Iron and Carbon.
STRUCTURE
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Alloys consist of
different atoms of
different sizes.
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This makes it difficult for
alloy layers to slide over
each other
PROPERTIES
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Alloys are created for their
desirable characteristics
such as:
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Strength, hardness,
durability, and weight.
Examples:
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Steel
 A mixture between iron ore
and carbon
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Alloy rims
 A mixture of Aluminum
and other metals
ALLOYS
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Extremely strong and
durable due to the
arrangement of atoms.
Can be created to meet
a certain material need.
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Stainless steel, made of
Chromium, Iron, and
Carbon, is resistant to rust
and other blemishes.
METALS
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Metals are relatively
soft and ductile.
They are easily molded
and shaped due to their
atomic arrangement.
Benjamin Oon and Sahas Chandragiri
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An alloy is a material that contains more than one
element and has the characteristic properties of a
metal.
Alloying of metals is one of the primary ways of
modifying properties of pure metallic elements.
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Most uses of iron involve alloy compositions (stainless steel) for
more convenient or sometimes efficient use.
Bronze formed by alloying copper and tin; brass is an alloy of
copper and zinc
Structures include Face Center
Cubic (left) and Cubic Center
Cubic (right).
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Homogeneous mixtures in which components are
dispersed randomly and uniformly.
 Solids that form homogeneous mixtures are
called solute solutions
A substitutional alloy occurs when atoms of the
solute solution occupy positions normally
occupied by a solvent atom
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This happens primarily due to the relative size of
each element – results in atom exchange.
The bonding between two metals is best described
as a combination of metallic electron "sharing" and
covalent bonding
Examples: bronze and brass (copper/tin and
copper/zinc)
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When the solute atoms occupy interstitial positions in
the “holes” between solvent atoms, the result is
interstitial alloys.
To form, the solute atoms must have a much smaller
bonding atomic radius than the solvent atoms.
Typically, the interstitial element is a nonmetal that
creates covalent bonds to the neighboring metal atoms.
 Examples: hydrogen, boron, carbon, nitrogen
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Compounds include transition metals, carbides, and
nitrides.
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Goal 8: Use chemical formulas to associate and
recognize and classification, structure and
bonding of solid substances
 Sam and Jacob
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Examples: Cu, Fe
If the chemical formula is a metallic element in
its monatomic form then it is a metallic solid
Metallic solids are made up of multiple atoms
of the same element by metallic bonding
 Pay attention to formulas and elements underneath
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Ionic Solids’ chemical formulas consist of a metal
and nonmetal ion.
Ionic solids are held together by ion- ion interactions
(ionic bonding).
 Examples: NaCl, MgO
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Molecular Solids’ chemical formulas are made up
of nonmetals.
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Molecular solids are held together with intermolecular
forces.
 Examples: H2O, HBr
https://www.youtube.com/watch?v=PKA4CZwbZWU
- First 3 and half minutes deal with this topic
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Examples: C, Si
Chemical formula consists of one or two
nonmetals, mostly from the carbon group.
Individual atoms are held together by a
network of covalent bonds.
https://www.youtube.com/watch?v=PU9rzTj
Lyb4
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First 2 minutes
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Using some common laboratory equipment
and materials, devise a plan to deduce the type
of bonding in a sample of an unknown solid.
Specify the tests you would perform and
discuss what the results mean.
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Conductivity: If it conducts, it is either a metal
or a covalent-network solid. If it has a high
conductivity, it is probably a metal
Add water to a portion: If it dissolves, it is
either an ionic solid or molecular solid. Test the
solution for conductivity: Ionic solids in
solution will conduct electricity, molecular
solids will not
Determine the melting point: Molecular solids
melt below 200oC.
Add acid to a portion: Some metals will
dissolve in acid and a gas will be produced.