Question 1

An alloy is a

Accepted Answer

A) heterogeneous mixture of two metals. 
B) pure metal. 
C) metallic material that is composed of two or more elements. 
D) nonmetal with some properties of a metal. 
E) mineral containing two or more metals. 
A) heterogeneous mixture of two metals. 
B) pure metal. 
C) metallic material that is composed of two or more elements. 
D) nonmetal with some properties of a metal. 
E) mineral containing two or more metals.

Question 2

The class of semiconductors, known as elemental, has special features. These are ________.

Accepted Answer

A) band gap and individual element valence electrons 
B) periodical table grouping and diamond crystal structure 
C) tetrahedral coordination geometry and sp2 hybrid orbitals 
D) overlapping hybrid orbitals and filed conduction bands 
E) none of the above 
A) band gap and individual element valence electrons 
B) periodical table grouping and diamond crystal structure 
C) tetrahedral coordination geometry and sp2 hybrid orbitals 
D) overlapping hybrid orbitals and filed conduction bands 
E) none of the above

Question 3

Blue LEDs are usually made of ________.

Accepted Answer

A) GaAs 
B) GaP 
C) GaO 
D) GaS 
E) GaN 
A) GaAs 
B) GaP 
C) GaO 
D) GaS 
E) GaN

Question 4

CsCl crystallizes in a unit cell that contains a Cs+ ion at the center of a cube and a Cl- ion at each corner. The unit cell of CsCl is ________.

Accepted Answer

A) close packed 
B) body-centered cubic 
C) face-centered cubic 
D) amorphous 
E) primitive cubic 
A) close packed 
B) body-centered cubic 
C) face-centered cubic 
D) amorphous 
E) primitive cubic

Question 5

Which of the following could be useful as an elemental semiconductor?

Accepted Answer

A) As 
B) Zn 
C) I 
D) K 
E) He 
A) As 
B) Zn 
C) I 
D) K 
E) He

Question 6

18 karat gold contains ________% gold.

Accepted Answer

A) 18 
B) 25 
C) 89 
D) 75 
E) 1.0 × 102 
A) 18 
B) 25 
C) 89 
D) 75 
E) 1.0 × 102

Question 7

When lattice points occur at the corners and at the center of a unit cell, the cell is called ________.

Accepted Answer

The answer of When lattice points occur at the corners...

Question 8

Write the chemical formulas for both polyethylene and the monomer from which it is formed.

Accepted Answer

The answer of Write the chemical formulas for both polyethylene...

Question 9

Which one of the following cannot form a solid with a lattice based on the sodium chloride structure?

Accepted Answer

A) NaBr 
B) LiF 
C) RbI 
D) CuO 
E) CuCl2 
A) NaBr 
B) LiF 
C) RbI 
D) CuO 
E) CuCl2

Question 10

The molecular-orbital model for Ge shows it to be

Accepted Answer

A) a conductor, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large. 
B) an insulator, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large. 
C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small. 
D) a semiconductor, because the gap between the filled lower and empty higher energy bands is large. 
E) a conductor, because its lower energy band orbitals are only partially filled. 
A) a conductor, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large. 
B) an insulator, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large. 
C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small. 
D) a semiconductor, because the gap between the filled lower and empty higher energy bands is large. 
E) a conductor, because its lower energy band orbitals are only partially filled.

Question 11

The properties of graphene include ________.

Accepted Answer

A) high strength 
B) low thermal conductivity 
C) a zero energy gap 
D) A and C 
E) A, B and C 
A) high strength 
B) low thermal conductivity 
C) a zero energy gap 
D) A and C 
E) A, B and C

Question 12

Which of the following is not classified as a nanomaterial?

Accepted Answer

A) isoprene 
B) buckminsterfullerene 
C) carbon nanotubes 
D) graphene 
E) All of the above are classified as nanomaterials 
A) isoprene 
B) buckminsterfullerene 
C) carbon nanotubes 
D) graphene 
E) All of the above are classified as nanomaterials

Question 13

6.0 karat gold contains ________% gold.

Accepted Answer

A) 6.0 
B) 25 
C) 50. 
D) 75 
E) 1.0 × 102 
A) 6.0 
B) 25 
C) 50. 
D) 75 
E) 1.0 × 102

Question 14

The formation of a condensation polymer generally involves ________.

Accepted Answer

A) the addition of a plasticizer 
B) the mixing of sulfur with an addition polymer 
C) the elimination of a small molecule 
D) the vaporization of a plasticizer 
E) the formation of significant crosslinking 
A) the addition of a plasticizer 
B) the mixing of sulfur with an addition polymer 
C) the elimination of a small molecule 
D) the vaporization of a plasticizer 
E) the formation of significant crosslinking

Question 15

The ________ lattice is one of the five two-dimensional lattices in which the lattice vectors a and b are equal and the γ angle between them is 90°.

Accepted Answer

A) square 
B) rectangular 
C) hexagonal 
D) rhombic 
E) oblique 
A) square 
B) rectangular 
C) hexagonal 
D) rhombic 
E) oblique

Question 16

________ solids consist of atoms or molecules held together by dipole-dipole forces, London dispersion forces, and/or hydrogen bonds.

Accepted Answer

A) Ionic 
B) Molecular 
C) Metallic 
D) Covalent-network 
E) Metallic and covalent-network 
A) Ionic 
B) Molecular 
C) Metallic 
D) Covalent-network 
E) Metallic and covalent-network

Question 17

The scattering of light waves upon passing through a narrow slit is called ________.

Accepted Answer

A) diffusion 
B) grating 
C) diffraction 
D) adhesion 
E) incidence 
A) diffusion 
B) grating 
C) diffraction 
D) adhesion 
E) incidence

Question 18

Metallic solids do not exhibit ________.

Accepted Answer

A) excellent thermal conductivity 
B) excellent electrical conductivity 
C) variable hardness 
D) extreme brittleness 
E) variable melting point 
A) excellent thermal conductivity 
B) excellent electrical conductivity 
C) variable hardness 
D) extreme brittleness 
E) variable melting point

Question 19

Natural rubber is too soft and chemically reactive for practical applications. Vulcanization of natural rubber entails ________.

Accepted Answer

A) conversion of an addition polymer to a condensation polymer 
B) conversion of a condensation polymer to an addition polymer 
C) increasing the average molecular weight of a condensation polymer 
D) decreasing the average molecular weight of an addition polymer 
E) crosslinking reactive polymer chains with sulfur atoms 
A) conversion of an addition polymer to a condensation polymer 
B) conversion of a condensation polymer to an addition polymer 
C) increasing the average molecular weight of a condensation polymer 
D) decreasing the average molecular weight of an addition polymer 
E) crosslinking reactive polymer chains with sulfur atoms

Question 20

Gallium crystallizes in a primitive cubic unit cell. The length of the unit cell edge is 3.70 Å. The radius of a Ga atom is ________ Å.

Accepted Answer

A) 7.40 
B) 3.70 
C) 1.85 
D) 0.930 
E) Insufficient data is given. 
A) 7.40 
B) 3.70 
C) 1.85 
D) 0.930 
E) Insufficient data is given.

Exam 12: Solids and Modern Materials

An alloy is a

The class of semiconductors, known as elemental, has special features. These are ________.

Blue LEDs are usually made of ________.

CsCl crystallizes in a unit cell that contains a Cs+ ion at the center of a cube and a Cl- ion at each corner. The unit cell of CsCl is ________.

Which of the following could be useful as an elemental semiconductor?

18 karat gold contains ________% gold.

When lattice points occur at the corners and at the center of a unit cell, the cell is called ________.

Write the chemical formulas for both polyethylene and the monomer from which it is formed.

Which one of the following cannot form a solid with a lattice based on the sodium chloride structure?

The molecular-orbital model for Ge shows it to be

The properties of graphene include ________.

Which of the following is not classified as a nanomaterial?

6.0 karat gold contains ________% gold.

The formation of a condensation polymer generally involves ________.

The ________ lattice is one of the five two-dimensional lattices in which the lattice vectors a and b are equal and the γ angle between them is 90°.

________ solids consist of atoms or molecules held together by dipole-dipole forces, London dispersion forces, and/or hydrogen bonds.

The scattering of light waves upon passing through a narrow slit is called ________.

Metallic solids do not exhibit ________.

Natural rubber is too soft and chemically reactive for practical applications. Vulcanization of natural rubber entails ________.

Gallium crystallizes in a primitive cubic unit cell. The length of the unit cell edge is 3.70 Å. The radius of a Ga atom is ________ Å.

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Stoichiometry: Calculations With Chemical Formulas and Equations

Aqueous Reactions and Solution Stoichiometry

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

CsCl crystallizes in a unit cell that contains a Cs⁺ ion at the center of a cube and a Cl^- ion at each corner. The unit cell of CsCl is ________.