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Crystalline and Amorphous Solids Flashcards
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Crystalline and Amorphous Solids Flashcards
Crystalline and Amorphous Solids Flashcards
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1
Question
What distinguishes crystalline solids from amorphous solids in terms of atomic arrangement?
Page 1
Answer
Crystalline solids have regular, periodic arrangement; amorphous have random arrangement
2
Question
What is long-range order in the context of crystalline materials?
Page 1
Answer
Regular, periodically repeated atomic structure throughout the sample
3
Question
Give examples of metallic crystalline materials.
Page 1
Answer
Copper, silver, aluminum
4
Question
What are examples of non-metallic crystalline materials?
Page 1
Answer
Germanium, silicon
5
Question
What are examples of amorphous materials?
Page 1
Answer
Glass, rubber, plastic
6
Question
How does the shape of crystalline materials differ from amorphous ones?
Page 2
Answer
Crystalline have definite geometric shape; amorphous do not
7
Question
What property makes crystalline materials anisotropic?
Page 2
Answer
Physical properties vary with direction
8
Question
Why do crystalline solids have sharp melting points?
Page 2
Answer
Due to regular atomic arrangement
9
Question
What is the internal symmetry in crystalline materials?
Page 2
Answer
Possessed by crystalline; absent in amorphous
10
Question
Define a crystalline solid.
Page 2
Answer
Periodic arrangement of atoms in three dimensions
11
Question
What are examples of metallic crystals?
Page 2
Answer
Cu, Ag, Al, Mg
12
Question
What makes amorphous solids isotropic?
Page 2
Answer
No directional properties due to random arrangement
13
Question
Why do amorphous solids have a wide melting range?
Page 2
Answer
Lack of regular structure
14
Question
Define space lattice.
Page 3
Answer
Regular, periodic arrangement of infinite points in 3D space
15
Question
What is a basis or motif in crystal structure?
Page 3
Answer
Group of atoms at every lattice point
16
Question
How is a crystal defined in terms of lattice and basis?
Page 3
Answer
Crystal = Space lattice + Basis
17
Question
What is a single crystal?
Page 3
Answer
Entire material consists of one crystal
18
Question
Give examples of single crystals.
Page 3
Answer
KDP, ADP
19
Question
What defines polycrystalline material?
Page 3
Answer
Collection of many small crystals separated by boundaries
20
Question
Give examples of polycrystalline materials.
Page 3
Answer
GaP, GaAs, ZnO, ZnS
21
Question
What is a fundamental translation vector in 2D?
Page 4
Answer
R = n1 a + n2 b
22
Question
How is the position vector represented in 3D space lattice?
Page 4
Answer
R = n1 a + n2 b + n3 c
23
Question
What are interfacial angles in crystals?
Page 4
Answer
Angles between crystallographic axes: α, β, γ
24
Question
Define unit cell.
Page 4
Answer
Smallest geometric volume with atoms in 3D
25
Question
What is a primitive cell?
Page 5
Answer
Smallest unit cell with lattice points only at corners
26
Question
Define lattice constant.
Page 5
Answer
Distance between successive lattice points along directions
27
Question
What is the number of atoms per unit cell?
Page 5
Answer
Total atoms present or shared by the unit cell
28
Question
Define atomic radius.
Page 5
Answer
Half the distance between nearest neighbor atoms
29
Question
What is coordination number?
Page 5
Answer
Number of nearest neighboring atoms to a given atom
30
Question
Define atomic packing factor (APF).
Page 5
Answer
Ratio of atomic volumes to unit cell volume