Physical Chemistry.ppt

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Chemistry Department of Fudan University
Physical Chemistry
Chapter VII Solid State
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Chemistry Department of Fudan University
Chapter VII Solid State
we couldn't live without their mechanical properties…
metal
polymer
oxide
polymer
Ca10(PO4)6OH2
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Chemistry Department of Fudan University
we couldn't live without their electronic properties…
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Chemistry Department of Fudan University
C M S M a s t e r s : Electronic Structure and Chemistry of Solids.
© Mark S. Golden 2002
Chemical classification:
molecular
ionic
covalent
metallic
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Chemistry Department of Fudan University
Solids
Amorphous solids: no repeating pattern, only short range order, extensively disordered - non crystalline
Crystals: highly regular arrangement of atoms, ions, molecules - periodic (repeating)
correlation with physical properties:
Regular shapes;
Anisotropy: a substance whose physical properties are difference in different directions.
A sharp melting point
Homogeneous
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Chemistry Department of Fudan University
STM下的Si晶体
来自于巴基斯坦的黄玉晶体
来自于加拿大魁北克的钙柱石(黄)和透辉石(蓝)
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Chemistry Department of Fudan University
Early ideas
A crystal has flat faces that are at chatacteristic angles to each other
Crystals have symmetry (Kepler) and long range order
Spheres and small shapes can be packed to produce regular shapes (Hooke, Hauy)
?
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Chemistry Department of Fudan University
Group discussion
Kepler wondered why snowflakes have 6 corners, never 5 or 7. By considering the packing of polygons in 2 dimensions, demonstrate why pentagons and heptagons shouldn’t occur.
Empty space not allowed
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Chemistry Department of Fudan University
All . Escher works (c) Cordon Art-Baarn-herlands.All rights reserved.
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Chemistry Department of Fudan University
Primitive Cell: simplest cell, contain one lattice point
Not necessary have the crystal symmetry
UNIT CELL = The ponent o