Question 1

Ceramic insulators

Accepted Answer

A) do not have a band structure. 
B) have a band structure, but no electrons are in these bands. 
C) have two half-filled bands, neither of which is capable of conducting electricity. 
D) have a full band that is well separated in energy from an empty band. 
E) do not exist, as all ceramics are good thermal and electrical conductors. 
A) do not have a band structure. 
B) have a band structure, but no electrons are in these bands. 
C) have two half-filled bands, neither of which is capable of conducting electricity. 
D) have a full band that is well separated in energy from an empty band. 
E) do not exist, as all ceramics are good thermal and electrical conductors.

Question 2

When silicon (Si) is doped with gallium (Ga), electrical conductivity increases because gallium

Accepted Answer

A) has fewer valence electrons than silicon so holes are created in the valence band of silicon. 
B) has more valence electrons than silicon so electrons are added to the conduction band of silicon. 
C) causes electrons to be transferred from the valence band of silicon to the conduction band of silicon. 
D) causes electrons to be transferred from the conduction band of silicon to the valence band of silicon. 
E) is a better conductor of electricity than silicon. 
A) has fewer valence electrons than silicon so holes are created in the valence band of silicon. 
B) has more valence electrons than silicon so electrons are added to the conduction band of silicon. 
C) causes electrons to be transferred from the valence band of silicon to the conduction band of silicon. 
D) causes electrons to be transferred from the conduction band of silicon to the valence band of silicon. 
E) is a better conductor of electricity than silicon.

Question 3

Polonium crystallizes in a simple cubic pattern.How many polonium atoms are in each unit cell?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 4

Researchers at the University of Texas at Austin prepared a linear allotrope of carbon in 1998.What is the hybridization of its atomic orbitals?

Accepted Answer

A) sp 
B) sp2 
C) sp3 
D) dsp3 
E) Cannot be determined from the information provided. 
A) sp 
B) sp2 
C) sp3 
D) dsp3 
E) Cannot be determined from the information provided.

Question 5

In comparing the density of bronze composed of 20% tin (r =140 pm, 7.37 g/cm3) to the density of pure copper (r =128 pm, 8.92 g/cm3),

Accepted Answer

A) the density of the bronze is lower. 
B) the density of the bronze is higher. 
C) the density of the bronze is the same. 
D) the density of the bronze depends on whether the tin or the copper occupies holes. 
E) It cannot be determined as only the 1:1 intermetallic compound of tin and copper has ever been observed. 
A) the density of the bronze is lower. 
B) the density of the bronze is higher. 
C) the density of the bronze is the same. 
D) the density of the bronze depends on whether the tin or the copper occupies holes. 
E) It cannot be determined as only the 1:1 intermetallic compound of tin and copper has ever been observed.

Question 6

Which of the following is NOT associated with the production of iron from iron ore in blast furnaces?

Accepted Answer

A) Iron ore, coke, and limestone are used. 
B) Solid by-products collect on top of molten iron, which is removed from the bottom of the reaction vessel. 
C) Molten iron crystallizes at its melting point of  C in a bcc structure but then undergoes a phase transition at around  C to an fcc structure. 
D) Limestone (CaCO3) decomposes to form lime (CaO), which can react with silica impurities (SiO2) in the iron ore. 
E) The carbon content is reduced by heating the impure molten iron in a second furnace to temperatures above  C. 
A) Iron ore, coke, and limestone are used. 
B) Solid by-products collect on top of molten iron, which is removed from the bottom of the reaction vessel. 
C) Molten iron crystallizes at its melting point of  C in a bcc structure but then undergoes a phase transition at around  C to an fcc structure. 
D) Limestone (CaCO3) decomposes to form lime (CaO), which can react with silica impurities (SiO2) in the iron ore. 
E) The carbon content is reduced by heating the impure molten iron in a second furnace to temperatures above  C.

Question 7

Why does a pure metal NOT crystallize in a fluorite or antifluorite unit cell?

Accepted Answer

A) They can and do. 
B) These unit cells require two types of atoms or ions with differing radii. 
C) Pure metals do not crystallize; they are amorphous. 
D) The atoms in pure metals move about in a sea of electrons. 
E) The radius of metal atoms is too large. 
A) They can and do. 
B) These unit cells require two types of atoms or ions with differing radii. 
C) Pure metals do not crystallize; they are amorphous. 
D) The atoms in pure metals move about in a sea of electrons. 
E) The radius of metal atoms is too large.

Question 8

Aluminum (Al) crystallizes as a face-centered unit cell with an edge length of 404 pm.What is the atomic radius of aluminum?

Accepted Answer

A) 143 pm 
B) 202 pm 
C) 286 pm 
D) 175 pm 
E) 808 pm 
A) 143 pm 
B) 202 pm 
C) 286 pm 
D) 175 pm 
E) 808 pm

Question 9

When germanium (Ge) is doped with gallium (Ga), it produces (an) _______ -type semiconductor.

Accepted Answer

The answer of When germanium (Ge) is doped with gallium...

Question 10

A rock salt structure has smaller ions in

Accepted Answer

A) cubic holes. 
B) tetrahedral holes. 
C) hexagonal holes. 
D) octahedral holes. 
E) the usual atomic positions in the unit cell i.e., not in holes). 
A) cubic holes. 
B) tetrahedral holes. 
C) hexagonal holes. 
D) octahedral holes. 
E) the usual atomic positions in the unit cell i.e., not in holes).

Question 11

Which of these is the best conductor of electricity?

Accepted Answer

A) diamond 
B) graphite 
C) water 
D) glass 
E) fullerene 
A) diamond 
B) graphite 
C) water 
D) glass 
E) fullerene

Question 12

Considering the elements C, Si, Ge, and Sn, which are semiconductors?

Accepted Answer

A) C and Si 
B) Si and Ge 
C) Ge and Sn 
D) None of these elements are semiconductors unless a dopant is added. 
E) All of these elements are semiconductors. 
A) C and Si 
B) Si and Ge 
C) Ge and Sn 
D) None of these elements are semiconductors unless a dopant is added. 
E) All of these elements are semiconductors.

Question 13

In which of the following is (are) the packing efficiency(ies) the lowest?
I.tungsten, bcc
II.titanium, hcp
III.nickel, fcc
IV.polonium, sc

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) III and IV 
A) I 
B) II 
C) III 
D) IV 
E) III and IV

Question 14

The $\alpha$ form of polonium (Po) crystallizes as a simple cubic unit cell with an edge length of 335 pm.What is the atomic radius of polonium?

Accepted Answer

A) 84 pm 
B) 168 pm 
C) 335 pm 
D) 175 pm 
E) 808 pm 
A) 84 pm 
B) 168 pm 
C) 335 pm 
D) 175 pm 
E) 808 pm

Question 15

Compare the packing efficiency of face-centered cubic gold and face-centered cubic sodium chloride.

Accepted Answer

A) Packing efficiencies cannot be defined for one or both of these. 
B) The efficiency of packing in the gold unit cell is higher. 
C) The efficiencies of packing in the two lattices are the same. 
D) The efficiency of packing in the sodium chloride unit cell is higher. 
E) There is no way to compare without further information. 
A) Packing efficiencies cannot be defined for one or both of these. 
B) The efficiency of packing in the gold unit cell is higher. 
C) The efficiencies of packing in the two lattices are the same. 
D) The efficiency of packing in the sodium chloride unit cell is higher. 
E) There is no way to compare without further information.

Question 16

Copper crystallizes in a face-centered cubic pattern.How many copper atoms are in each unit cell?

Accepted Answer

A) 2 
B) 4 
C) 8 
D) 12 
E) 14 
A) 2 
B) 4 
C) 8 
D) 12 
E) 14

Question 17

Electrical and thermal conductivity in metals is

Accepted Answer

A) explained by a dipolar coupling model. 
B) explained by band theory. 
C) explained by ionic bonding. 
D) explained by temporary ionization. 
E) a function of the level of contamination by excess electrons. 
A) explained by a dipolar coupling model. 
B) explained by band theory. 
C) explained by ionic bonding. 
D) explained by temporary ionization. 
E) a function of the level of contamination by excess electrons.

Question 18

Aluminum alloys are more desirable than steel in some applications because of their relatively

Accepted Answer

A) low density. 
B) low cost. 
C) high luster. 
D) high thermal conductivity. 
E) high conductivity. 
A) low density. 
B) low cost. 
C) high luster. 
D) high thermal conductivity. 
E) high conductivity.

Question 19

According to band theory, when the lower-energy _____band overlaps with the higher-energy_____band, the material will act as a(n)_____ of electricity.

Accepted Answer

valence; c

Question 20

What is the type of bonding that occurs between carbon atoms in diamond?

Accepted Answer

A) pi bonding 
B) sigma bonding 
C) both pi and sigma bonding 
D) neither pi nor sigma bonding 
E) ionic bonding 
A) pi bonding 
B) sigma bonding 
C) both pi and sigma bonding 
D) neither pi nor sigma bonding 
E) ionic bonding

Exam 18: The Solid State a Particulate View

Ceramic insulators

When silicon (Si) is doped with gallium (Ga), electrical conductivity increases because gallium

Polonium crystallizes in a simple cubic pattern.How many polonium atoms are in each unit cell?

Researchers at the University of Texas at Austin prepared a linear allotrope of carbon in 1998.What is the hybridization of its atomic orbitals?

In comparing the density of bronze composed of 20% tin (r =140 pm, 7.37 g/cm3) to the density of pure copper (r =128 pm, 8.92 g/cm3),

Which of the following is NOT associated with the production of iron from iron ore in blast furnaces?

Why does a pure metal NOT crystallize in a fluorite or antifluorite unit cell?

Aluminum (Al) crystallizes as a face-centered unit cell with an edge length of 404 pm.What is the atomic radius of aluminum?

When germanium (Ge) is doped with gallium (Ga), it produces (an) _______ -type semiconductor.

A rock salt structure has smaller ions in

Which of these is the best conductor of electricity?

Considering the elements C, Si, Ge, and Sn, which are semiconductors?

In which of the following is (are) the packing efficiency(ies) the lowest? I.tungsten, bcc II.titanium, hcp III.nickel, fcc IV.polonium, sc

The α\alphaα form of polonium (Po) crystallizes as a simple cubic unit cell with an edge length of 335 pm.What is the atomic radius of polonium?

Compare the packing efficiency of face-centered cubic gold and face-centered cubic sodium chloride.

Copper crystallizes in a face-centered cubic pattern.How many copper atoms are in each unit cell?

Electrical and thermal conductivity in metals is

Aluminum alloys are more desirable than steel in some applications because of their relatively

According to band theory, when the lower-energy _____band overlaps with the higher-energy_____band, the material will act as a(n)_____ of electricity.

What is the type of bonding that occurs between carbon atoms in diamond?

Matter and Energy an Atomic Perspective

Atoms, Ions, and Molecules the Building Blocks of Matter

Atomic Structure Explaining the Properties of Elements

Chemical Bonding Understanding Climate Change

Bonding Theories Explaining Molecular Geometry

Intermolecular Forces Attractions Between Particles

Stoichiometry Mass Relationships and Chemical Reactions

Aqueous Solutions Chemistry of the Hydrosphere

Thermochemistry Energy Changes in Chemical Reactions

Properties of Gases the Air We Breathe

Properties of Solutions Their Concentrations and Colligative Properties

Thermodynamics Why Chemical Reactions Happen

Chemical Kinetics Clearing the Air

Chemical Equilibrium Equal but Opposite Reaction Rates

Acid-Base Equilibria Proton Transfer in Biological Systems

Additional Aqueous Equilibria Chemistry and the Oceans

Electrochemistry the Quest for Clean Energy

Organic Chemistry Fuels, Pharmaceuticals, and Modern Materials

Biochemistry the Compounds of Life

Nuclear Chemistry the Risks and Benefits

The Main Group Elements Life and the Periodic Table

Transition Metals Biological and Medical Applications

Filters

In comparing the density of bronze composed of 20% tin (r =140 pm, 7.37 g/cm3) to the density of pure copper (r =128 pm, 8.92 g/cm³),

The $\alpha$ form of polonium (Po) crystallizes as a simple cubic unit cell with an edge length of 335 pm.What is the atomic radius of polonium?

According to band theory, when the lower-energy ___band overlaps with the higher-energy_band, the material will act as a(n)___ of electricity.