Chapter 10 Section 3

1
Chapter 10 Section 3 The Nature of Solids
Tessa Murray Mary Rose Gawbill Ryan
Curran Christina Bartkus Gabriele Frattarola
2
Overview

• A Model for Solids
• A solids structure
• Kinetic energy in a solid
• Melting and boiling points of solids
• Crystal Structure and Unit Cells
• Seven Crystal Systems
• Unit Cells
• Allotropes
• Amorphous Solids
• Glass

3
A Model for Solids

• Solids have fixed points
• Solids are packed in an organized pattern
• Solids are incompressible
• The packed particles explain a solids
  incompressibility and definite shape and volume
• http//intro.chem.okstate.edu/1314F00/Lecture/
• Chapter1/MicroStates.html

4
Kinetic Energy

• Kinetic energy- energy of motion
• Any object in motion has kinetic energy
• Heat increases kinetic energy
• Kinetic energy breaks down and melts a solid

Clipart From Microsoft PowerPoint
5
Melting Point

• Melting Point (MP)- temperature at which a solid
  turns into a liquid
• A Solid melts when particle vibrations disrupt
  the structure
• MP is reversed by freezing
• Melting freezing points are the same
  temperature
• At that temperature, liquids and solids are in
  equilibrium with each other

Clipart From Microsoft PowerPoint
6
Other MPs

• Ionic solids have a high MP
• held together by strong forces
• Sodium Chloride 801 Celsius
• Molecular compounds have low MP
• weak intermolecular forces
• Hydrogen Chloride -112 Celsius
• Some solids decompose when heated
• Wood and sugar cane

Ionic Compound NaCl MP800.8 C

Molecular Compound H20 MP 0 C
http//www.chemcool.com/regents/chemicalbonding/ai
m5.htm
7
Unit Cell

• Smallest group of particles within crystal
• Retains geometric shape
• Crystal lattice
• repeating
• One of fourteen unit cells
• Crystal system has from 1 4 types associated
  with system

8
Unit Cells in Cubic Crytsal System
In a Body-Centered Cubic unit cell, the atoms or
ions are at the corners and in the center of an
imaginary cube.
In a Simple Cubic Unit cell, the atoms Or ions
are arranged At the corners of an Imaginary cube.
In a face-centered cubic Unit Cell, the atoms or
ions are in the center of each face of the
imaginary cube (but there is no atom or ion in
the center)
Textbook pg. 282
9
Crystal Structure

• Atoms, ions, or molecules arranged in orderly,
  repeating, 3D pattern crystal lattice
• Reg. shape
• Reflects the arrangement of the particles
• Melting point
• Type of bonding determines melting point
• Groups or crystal systems
• classified into 7 groups

10
Crystal Systems

• Differ in terms of angles between the faces and
  in the number of edges of equal length on each
  face
• Galena cubic
• Zircon tetragonal
• Topaz orthorhombic
• Gypsum monoclinic
• Amazonite triclinic
• Tourmaline hexagonal
• Calcite - rhombohedral

11
Seven Crystal Systems
Textbook pg 281
12
Seven Crystal Systems
Textbook pg 281
13
Seven Crystal Systems
Textbook pg 281
14
Allotropes

• Definition Different molecular forms of the same
  substance in the same physical state
• More than one way to for the atoms to combine to
  form molecules

15
Allotropes

• Same atoms of a substance, but different
  molecular form and new properties
• Carbon
• diamond
• graphite
• buckyball

Diamond
Graphite
Buckyball
Textbook Pg 283
16
Amorphous Solids

• They are solids that lack an ordered internal
  structure.
• They are also known to have no long-range order,
  meaning the characterization of physical systems
  in remote portions of the same sample exhibit
  correlated behavior.
• They are any non-crystalline solid in which the
  atoms and molecules are not organized in a
  definite lattice.
• A lattice is defined as a structure of
  fissionable and nonfissionable materials
  geometrically arranged within a nuclear reactor.

17
Examples of Amorphous Solids

• Glasses are transparent fusion products of
  inorganic substances that have cooled to a rigid
  state without crystallizing
• Other examples are rubber, plastic, asphalt, and
  the silicon in many thin film solar cells.

http//www.fau.edu/divdept/physics/jordanrg/LLS/le
cture15/VG41.GIF
18
Glasses

• They are often called super cooled liquids.
• The internal structure of glasses are
  characterized between those of a crystalline
  solid and a free-flowing liquid.
• Glasses gradually soften when heated instead of
  melting at a definite point.
• When shattered, the fragments from the glass will
  have irregular angles and jagged edges.

http//www.jst.go.jp/erato/project/hyk_P/icons/grf
2_1.jpg
19
References

• http//intro.chem.okstate.edu/1314F00/Lecture/Chap
  ter1/MicroStates.html
• http//www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/e
  nergy/u5l1c.html
• http//www.saltinstitute.org/15.html
• http//web.mit.edu/iap/www/iap04/searchiap/iap-487
  7.html
• http//www.chemcool.com/regents/chemicalbonding/ai
  m5.htm
• http//www.wisegeek.com/what-is-an-allotrope.htm
• http//hypertextbook.com/physics/matter/polymorphs
  /
• http//www.britannica.com/eb/article-9110300/amorp
  hous-solid
• http//dictionary.reference.com/browse/lattice20
• http//dwb.unl.edu/Teacher/NSF/C01/C01Links/www.ua
  lberta.ca/bderksen/florin.html
• http//en.wikipedia.org/wiki/Long-range_order
• http//www.utmem.edu/physpharm/.003a.html
• Chemistry Textbook pgs. 280-283