Deck 12: Solids

Question 1

A cubic unit cell with eight component atoms, molecules, or ions located at the corners of a cube plus an identical component in the center of the cube is called a _____.

A) simple cubic
B) body-centered cubic
C) face-centered cubic
D) hexagonal close-packed structure
E) cubic close-packed structure

Answer 1

body-centered cubic

Question 2

The coordination number of a hexagonal close-packed structure is _____.

A) 3
B) 4
C) 6
D) 12
E) 8

Answer 2

12

Question 3

If a unit cell contains an identical component in the center of the cube, along with the eight component atoms, molecules, or ions located at the corners of the cube, then it is called a face-centered cubic.

Answer 3

False

Question 4

A regular repeating three-dimensional structure formed by the constituents of a solid is called a(n) _____.

Question 5

Which of the following unit cells has sides that have the same length but the angles between them is not equal to 90˚?

A) Monoclinic
B) Rhombohedral
C) Tetragonal
D) Orthorhombic
E) Triclinic

Question 6

Differentiate between a body centered cubic and a face centered cubic.

Question 7

What are the characteristic properties of amorphous solids?

Question 8

An atom or ion in a cubic hole has a coordination number of 6.

Question 9

Density is the mass of substance per unit volume.

Question 10

_____ is an amorphous, translucent solid that has been cooled rapidly to form ordered crystals.

Question 11

Amorphous solids have sharp, well-defined melting points.

Question 12

A solid with a regular repeating three-dimensional structure is called a(n) _____.

A) metallic solid
B) alloy
C) crystalline solid
D) amorphous solid
E) colloid

Question 13

Crystalline solids differ from amorphous solids as amorphous solids:

A) melt over a wide range of temperatures.
B) have components arranged in a regular repeating array.
C) have distinctive flat surfaces that intersect at particular angles.
D) have well defined edges and faces.
E) provide well resolved x-ray diffraction patterns.

Question 14

A cubic unit cell that consists of only eight component atoms, molecules, or ions located at the corners of the cube is called a _____.

A) hexagonal close-packed structure
B) simple cubic
C) body-centered cubic
D) face-centered cubic
E) cubic close-packed structure

Question 15

The type of unit cell in which all sides have the same length and all angles between them is 90˚ is a(n) _____ unit.

A) rhombohedral
B) hexagonal
C) orthorhombic
D) cubic
E) tetragonal

Question 16

The smallest repeating unit of a crystal lattice is called a(n) _____.

Question 17

A crystalline solid has no particular structural order.

Question 18

Which of the following is an amorphous solid?

A) Galena
B) Pyrite
C) Rock salt
D) Quartz glass
E) Granite

Question 19

For all unit cells except hexagonal, atoms on the edges contribute ¼ atom to each unit cell.

Question 20

The number of nearest neighbours in a solid structure is called the _____.

Question 21

A 1:1 cation:anion ratio and a coordination number of 8 for both the cation and the anion is a characteristic of a _____ structure.

A) perovskite
B) cesium chloride
C) sodium chloride
D) zinc blende
E) rock salt

Question 22

A(n) _____ is a point defect that consists of a single atom missing from a site in a crystal.

A) deformation
B) vacancy
C) interstitial impurity
D) edge dislocation
E) substitutional impurity

Question 23

What is Bragg equation? How is it useful in determining the structures of crystalline solids?

Question 24

The hole located at the center of the simple cubic lattice is called a _____.

Question 25

An atom or ion in an octahedral hole has a coordination number of _____.

A) 4
B) 3
C) 6
D) 8
E) 12

Question 26

A hole that is located in the center of the face-centered cubic unit cell and as a shared one in the middle of each edge is called a(n) _____ hole.

A) cubic
B) trigonal
C) perovskite
D) octahedral
E) tetrahedral

Question 27

A distortion that occurs when a dislocation moves through a crystal is known as ____.

A) edge dislocation
B) substitutional impurity
C) vacancy
D) deformation
E) interstitial impurity

Question 28

Schottky defect is a defect in an ionic lattice that occurs when one of the ions is in a wrong position.

Question 29

Occupation of half the tetrahedral holes by cations in an fcc lattice of anions, results in the sodium chloride structure.

Question 30

Intersecting dislocations in a solid increases the mechanical strength of the material.

Question 31

A substitutional impurity is a different atom of about the same size that simply replaces one of the atoms that compose the host lattice.

Question 32

_____ is a technique used to obtain information about the structures of crystalline substances using x-rays.

Question 33

A crystal defect that results from the insertion of an extra plane of atoms into part of the crystal lattice is called a(n) _____.

A) deformation
B) vacancy
C) interstitial impurity
D) edge dislocation
E) line defect

Question 34

A hole that is located between an atom at a corner and the three atoms at the centers of the adjacent faces of the face-centered cubic unit cell is called a(n) _____.

A) cubic hole
B) trigonal hole
C) perovskite structure
D) octahedral hole
E) tetrahedral hole

Question 35

A point defect that results when an impurity atom occupies a normal lattice site is called a(n) _____.

A) edge dislocation
B) substitutional impurity
C) vacancy
D) deformation
E) interstitial impurity

Question 36

Larger cations have higher coordination numbers than small cations.

Question 37

The solid structure that results when half of the tetrahedral holes in an fcc lattice of anions are filled with cations with a 1:1 cation:anion ratio and a coordination number of 4 is called the _____.

A) sodium chloride structure
B) zinc blende structure
C) interpenetrating primitive cubic structure
D) cesium chloride structure
E) rock salt structure

Question 38

A structure that consists of a bcc array of two metal ions, with one set(M) located at the corners of the cube and the other set(M′) in the center of the cube is called the _____.

A) sodium chloride structure
B) zinc blende structure
C) interpenetrating primitive cubic structure
D) cesium chloride structure
E) perovskite structure

Question 39

A defect in a crystal that affects only a single particle in the lattice is called a(n) _____.

A) plane defect
B) line defect
C) point defect
D) edge dislocation
E) deformation

Question 40

If the octahedral holes in an fcc lattice of anions are filled with cations, the result is a _____ structure.

A) sodium chloride
B) zinc blend
C) perovskite
D) potassium blend
E) nitrogen chloride

Question 41

A solid that consists of atoms or molecules held together by relatively weak forces such as dipole-dipole interactions, London dispersion forces and hydrogen bonds is called a(n) _____ solid.

A) molecular
B) metallic
C) atomic
D) ionic
E) covalent

Question 42

What are nonstoichiometric compounds? Give any two examples.

Question 43

A solid material with a very high electrical conductivity is called a(n) _____.

Question 44

Covalent solids differ from metallic solids as metallic solids:

A) have low density.
B) have a dull surface.
C) are ductile and malleable and easily deform under stress.
D) have atoms held together by covalent bonds.
E) are poor conductors of heat and electricity.

Question 45

An alloy formed by inserting smaller atoms into holes in the metal lattice is called a(n) _____ alloy.

A) amalgam
B) interstitial
C) substitutional
D) intermetallic
E) covalent

Question 46

Which of the following statements is true regarding molecular solids?

A) Molecular solids are good conductors of heat and electricity.
B) Molecular solids tend to have low melting points.
C) Molecular solids are lustrous.
D) Molecular solids usually have high density.
E) Molecular solids tend to be Hard.

Question 47

Every lattice point in a pure metallic element is occupied by an atom of the same metal.

Question 48

A(n) _____ alloy is an alloy formed by the replacement of one metal atom for another of similar size in the lattice.

A) molecular
B) covalent
C) substitutional
D) interstitial
E) intermetallic

Question 49

A defect in an ionic lattice that occurs when one of the ions is in the wrong position is called a(n) _____.

A) plane defect
B) line defect
C) Frenkel defect
D) Schottky defect
E) edge dislocation

Question 50

Differentiate between ionic solids and molecular solids.

Question 51

The valence electrons that are delocalized throughout a metallic solid are referred to as the _____.

Question 52

Graphite, a covalent solid, is a bad conductor of electricity.

Question 53

The practice of introducing a dense network of dislocations throughout a solid, to make it very tough and Hard is known as _____.

Question 54

A solid that consists of positively and negatively charged ions held together by electrostatic forces is called a(n) _____.

A) intermetallic compound
B) ionic solid
C) covalent solid
D) molecular solid
E) metallic solid

Question 55

Alloys that consist of certain metals that combine in only specific proportions and whose properties are frequently quite different from those of their constituent elements are called _____.

Question 56

A process that increases the mechanical strength of a material by introducing multiple defects into a material so that the presence of one defect prevents the motion of another is called _____.

A) sintering
B) pinning
C) work Hardening
D) pyrolysis
E) doping

Question 57

The place where two grains in a solid intersect is called a(n) _____.

Question 58

A coupled pair of vacancies, a cation and an anion, that maintains the electrical neutrality of an ionic solid is called a(n) _____.

A) Schottky defect
B) edge dislocation
C) vacancy
D) line defect
E) Frenkel defect

Question 59

A solid solution of two or more metals whose properties differ from those of the constitutional elements is called a(n) _____.

Question 60

A perfect single crystal of a covalent solid is a single giant molecule.

Question 61

List out the properties of metals as explained by the band theory.

Question 62

A substance that has conductivity between that of metals and insulators is called a(n) _____.

Question 63

A material that conducts electricity poorly because its valence bands are full is called a(n) _____.

A) strong electrolyte
B) electrical insulator
C) semiconductor
D) superconductor
E) diode

Question 64

The electrons in Cooper pairs change partners frequently.

Question 65

_____ represents a set of forbidden energies that do not correspond to any allowed combinations of atomic orbitals.

A) Band gap
B) Bandwidth
C) Energy band
D) Valence band
E) Conduction band

Question 66

_____ refers to a process of deliberately introducing small amounts of impurities into commercial semiconductors to tune their electrical properties for specific applications.

A) Sintering
B) Pyrolysis
C) Doping
D) Quenching
E) Firing

Question 67

A solid must have a set of delocalized orbitals forming a band of allowed energy levels that is partially occupied to exhibit metallic behavior.

Question 68

The molecular orbitals derived from two or more different kinds of valence electrons that have similar energies are called _____.

A) conduction bands
B) valence bands
C) energy bands
D) overlapping bands
E) electron sea

Question 69

Naturally occurring polymers with more than about 50 amino acid residues are called proteins.

Question 70

_____ are pairs of electrons that migrate through a superconducting material as a unit.

Question 71

The electrical conductivity of a metal increases with increasing temperature.

Question 72

The difference in energy between the highest and the lowest energy levels in an energy band is called a(n) _____.

A) valance band
B) bandwidth
C) band gap
D) induced gap
E) electron band

Question 73

Discuss the BCS theory which explains the phenomenon of superconductivity.

Question 74

According to the _____ theory, electrons are able to travel through a solid with zero resistance because of attractive interactions involving two electrons that are at some distance from each other.

Question 75

Biological polymers contain very few different monomers.

Question 76

The band of empty molecular orbitals in a semiconductor is called a(n) _____ band.

A) energy
B) overlapping
C) valence
D) conduction
E) radiation

Question 77

The phenomenon in which a solid at low temperatures exhibits zero resistance to the flow of electric current is called _____.

A) sintering
B) superconductivity
C) Meissner effect
D) pyrolysis
E) proximity effect

Question 78

_____, an approach to metallic bonding, assumes that the valence orbitals of the atoms in a solid interact, generating a set of molecular orbitals that extend throughout the solid.

Question 79

A solid that exhibits zero resistance to the flow of electrical current at low temperatures is called a semiconductor.

Question 80

The phenomenon in which a superconductor completely expels a magnetic field from its interior is called the _____ effect.

A) Meissner
B) valance
C) photoelectric
D) Schottky
E) Frenkel