TEST 1 REVIEW
The electrons that occupy the outermost filled shell are called _________ electrons. (a) Acceptor (b) Conduction (c) Valence (d) Various (e) Inner shell
(c) Valence
How many atoms or molecules are there in one mole of a substance? (a) 6.023*10^18 (b) 6.023*10^-18 (c) 6.023*10^-23 (d) 6.023*10^+23 (e) 6.023*10^24
(d) 6.023*10^+23 This is Avogadro's number
Which kind of fracture is associated with the intergranular crack propagation mechanism? (NOTE: Intergranular means between grains, transgranular means through grains). a) Ductile b) Brittle c) Both ductile and brittle d) None of the above
b) Brittle
In noncrystalline materials (i.e., glasses or amorphous materials), plastic deformation occurs by the motion of dislocations. Is this true or false? a) True b) False
b) False
Name the two general states that accompany a phase transformation. a) Innoculation b) Growth c) Nucleation d) Recovery e) Recrystallization
b) Growth c) Nucleation
Increased hindering of dislocation motion makes a crystalline material ___________. a) Softer b) Harder
b) Harder
In general, as the impurity concentration (in solid solution) of a metal is increased, the tensile and yield strengths will ___________. a) Decrease b) Increase c) Stay the same
b) Increase
An engineer is designing a plane. There is a choice of aluminum or a composite material. The composite weighs half that of aluminum. Choosing the composite will not affect fuel costs. a. True b. False
b. False
The ratio of sizes of the ionic radii of anions and cations in a cell has no influence on the manner of packing of that cell. a. True b. False
b. False
The valence of an atom is the number of electrons in an atom that do not participate in bonding in chemical reactions. a. True b. False
b. False
The electronegativities of titanium and oxygen are 1.5 and 3.5. Calculate the fraction of bonding that is covalent for titania ( TiO2)
fcovalent=.368
A binary composition-temperature phase diagram for an isomorphous system will be composed of regions that contain which of the following phases and/or combinations of phases? a) α b) Liquid + α c) Liquid d) Both (a) and (b) e) Both (b) and (c) f) Both (a) and (c) g) All of (a), (b), and (c)
g) All of (a), (b), and (c)
In all crystal structures, there are small holes between the usual atoms into which smaller atoms may be placed. These locations are called _____________.
interstitial sites
Most of the mass of the atom is contained within the ___________.
nucleus
Planes and their negative values are identical because they are ________________.
parallel
The Pauli Exclusion Principle states that within each atom, no two electrons can have the same four ___________ numbers.
quantum
What are some desirable characteristics of refractory ceramics? (a) Ability to withstand high temperatures (b) Ability to withstand low temperatures (c) Ability to remain unreactive and inert in severe environments (d) High strength (e) Low thermal conductivity (i.e., they are good insulators)
(a) Ability to withstand high temperatures (c) Ability to remain unreactive and inert in severe environments (e) Low thermal conductivity (i.e., they are good insulators)
Please select the correct answers. Silica refractory ceramics are often used for the containment of slags that are rich in: (a) CaO (b) CsCl (c) FeO (d) MgO (e) Silica (f) Al2O3 (g) MgAl2O4 (h) NaCl
(a) CaO (d) MgO (e) Silica
What are some desirable characteristics of aluminum? Please select the correct answer. (a) High specific strength (b) Low melting temperature (c) High corrosion resistance (d) High thermal conductivity (e) No endurance limit
(a) High specific strength (c) High corrosion resistance (d) High thermal conductivity
As the particle content is increased, how does the strength of a particle-reinforced composite change? (a) Increases (b) Decreases (c) Stays the same
(a) Increases
Coordination numbers (CN) refer to: (a) The number of nearest neighbors surrounding (i.e., bonded to) a particular atom or ion. (b) The number of vacant lattice sites. (c) The number of atoms or ions that can be placed inside a unit cell. (d) The number of formula units in a particular substance.
(a) The number of nearest neighbors surrounding (i.e., bonded to) a particular atom or ion.
Why do we add plasticizers to polymers? (a) To improve flexibility (b) To improve tensile strength (c) To improve compressive strength (d) To improve thermal stability (e) To improve toughness
(a) To improve flexibility (e) To improve toughness
What is the typical carbon concentration range for cast irons? (a) 4.5 wt% - 6.67 wt% C (b) 3.0 wt% - 4.50 wt% C (c) 1.0 wt% - 1.75 wt% C (d) 2.0 wt% - 3.50 wt% C (e) 1.0 wt% - 2.00 wt% C (f) 2.0 wt% - 3.00 wt% C
(b) 3.0 wt% - 4.50 wt% C
Hard magnetic materials display which of the following characteristics? Select the correct answers. (a) A relatively small hysteresis loop (b) A relatively large hysteresis loop (c) Magnetization and demagnetization may be achieved using relatively low applied fields (d) Magnetization and demagnetization may be achieved using relatively high applied fields
(b) A relatively large hysteresis loop (d) Magnetization and demagnetization may be achieved using relatively high applied fields
Please select the correct answers. Metals located near the bottom of the EMF series are: (a) Cathodic (b) Anodic (c) Unreactive (d) Reactive
(b) Anodic (d) Reactive
Which of the following materials are considered to be composites? (a) Aluminum oxide (b) Bone (c) Concrete (d) Epoxy (e) Fiberglass (f) Nickel
(b) Bone (c) Concrete (e) Fiberglass
The following describes which type of magnetism: permanent and aligned magnetic moments that result from the incomplete cancellation of magnetic spin moments; these are present even in the absence of an external field? (a) Antiferromagnetism (b) Ferrimagnetism (c) Paramagnetism (d) Ferromagnetism (e) Diamagnetism
(b) Ferrimagnetism
The oxidation of an atom is a process that involves the: (a) Gain of electrons (b) Loss of electrons
(b) Loss of electrons
Which of the following microconstituents/phases is (are) typically found in low carbon steel? (Select two answers) (a) Tempered martensite (b) Pearlite (c) Ferrite (d) Martensite (e) Austenite
(b) Pearlite (c) Ferrite
Covalent bonds are formed by: (a) Transfer of valence electrons from electropositive to electronegative atoms. (b) Sharing of valence electrons with opposite spins. (c) Weak electrostatic attractions between positively and negatively charged regions (d) Sharing of a sea of decoupled valence electrons. (e) None of the above
(b) Sharing of valence electrons with opposite spins.
The motif (aka basis) refers to: (a) An array of uniformly arranged points in space. (b) The objects that are placed on lattice points to build up a crystal structure. (c) The lattice parameters for a given crystal. (d) None of the above
(b) The objects that are placed on lattice points to build up a crystal structure.
Atoms are: (a) The largest unit of matter that retains the identity of a substance. (b) The smallest unit of matter that retains the identity of a substance. (c) The smallest unit of a substance that retains the can be used to deconstruct it. (d) None of the above
(b) The smallest unit of matter that retains the identity of a substance.
Plastics may be which of the following? (a) Thermoplastic (b) Thermosetting (c) Both of the above (d) None of the above
(c) Both of the above
The atomic number characterizes each element and is equivalent to: (a) The number of electrons orbiting the nucleus of an atom. (b) The summed mass of protons and neutrons in the nucleus of an atom. (c) The number of protons inside the nucleus of an atom. (d) Equal to 1/12 the mass of carbon 12.
(c) The number of protons inside the nucleus of an atom.
What differentiates atomic structures from crystal structures? (a) Atomic structure relates to the arrangement of protons and neutrons in the nucleus of an atom. Crystal structure pertains to the electron structure of the individual atoms. (b) Atomic structure relates to the number of protons and neutrons in the nucleus of an atom. Crystal structure pertains to the number and probability distributions of the electrons. (c) Atomic structure relates to the type of atomic bonding. Crystal structure pertains to the arrangement of atoms in the crystalline solid material. (d) Atomic structure relates to the number of electrons. Crystal structure pertains to the type of atomic bonding in the crystalline solid material. (e) Atomic structure relates to the number of protons and neutrons in the nucleus of an atom, as well as the number and probability distributions of the constituent electrons. Crystal structure pertains to the arrangement of atoms in the crystalline solid material.
(e) Atomic structure relates to the number of protons and neutrons in the nucleus of an atom, as well as the number and probability distributions of the constituent electrons. Crystal structure pertains to the arrangement of atoms in the crystalline solid material.
The nucleus of an atom contains which of the following particles. (a) Protons (b) Electrons (c) Neutrons (d) Both (a) and (b) (e) Both (a) and (c) (f) Both (b) and (c) (g) All of (a), (b), and (c) (h) None of the above
(e) Both (a) and (c) The nucleus of an atom contains both protons and neutrons.
Below are shown, for five metals, reduction reactions and standard electrode potential values. Which of these metals is the most reactive? (a) Au³⁺ + 3e⁻ →Au +1.420 V (b) Cu²⁺ + 2e- →Cu +0.340 V (c) Ni²⁺ + 2e- → Ni −0.25 V (d) Fe²⁺ + 2e- → Fe −0.440 V (e) Na¹⁺ + 1e- → Na −2.924 V
(e) Na¹⁺ + 1e- → Na −2.924 V
Which of the following materials may form crystalline solids? (a) Metals (b) Polymers (c) Ceramics (d) Both (a) and (b) (e) Both (b) and (c) (f) Both (a) and (c) (g) All of (a), (b), and (c) (h) None of the above
(g) All of (a), (b), and (c)
Consider two different ions. The first ion has a valence of 3+ while the second ion has a valence of 2-. The two ions are separated by a distance of 1.0 nm. Please calculate the force of attraction between the two ions.
Fa=-(Z₁e)(Z₂e)/(4πε₀r²)= -((3)(-2)(1.602*10^-19C)²) / ((4)(π)(8.85*10^-12 F/m)(1.0*10^-9m)² = 1.38*10^-9N
Impurity atoms in metals, ceramics, and alloys may form substitutional and interstitial solid solutions. a) True b) False
a) True
The surface energy of a single crystal depends on the crystallographic orientation with respect to the surface. a) True b) False
a) True
When light interacts with matter is said to be attenuated. Attenuation of light (aka how it interacts) by matter can occur in which of the following ways? Select the correct answers. a) absorption b) dispersion c) opacity d) reflection e) refraction f) scattering g) translucency h) transmission i) transparency
a) absorption d) reflection f) scattering h) transmission
The process by which plastic deformation is produced by dislocation motion is called ______. a) glide b) slick c) slide d) slip e) slope
a) glide d) slip
When referring to the optical properties of materials, _____[A]_____ materials are impervious to light transmission; whereas, _____[B]_____ materials transmit light diffusely and _____[C]_____ materials transmit light with little absorption. Please fill in the blanks with the proper answer. a) Opaque b) Translucent c) Transparent
[A] = (a), [B] = (b), [C] = c
For most technologically important metal alloys, the usual state or microstructure is: a) A metastable one b) An equilibrium one
a) A metastable one
Ceramics are said to be ionocovalent materials. This means that they have both ionic and covalent bond characteristics. For a ceramic that has 75% ionic bonding, the charge carriers can be which of the following? a) Anions b) Cations c) Electrons d) Frenkel defects e) Holes f) Schottky defects
a) Anions b) Cations c) Electrons e) Holes
In insulators and intrinsic semiconductors, what is the name of the region that lies above the energy band gap? a) Conduction band b) Valence band c) Acceptor state d) Donor state
a) Conduction band
What are two fundamental types of dislocations? a) Edge b) Screw c) Curved d) Vacancy e) Loop
a) Edge b) Screw
The thermal conductivities of single crystals are __________ those of polycrystalline materials. a) Greater than b) Less than c) Equal to
a) Greater than
For a particular crystal structure, the slip direction is that direction in the slip plane having the _________________. a) Highest linear density b) Intermediate linear density c) Lowest linear density
a) Highest linear density
What determines the characteristic color of a metal? Select the correct answer. a) The characteristic color is determined by the distribution of wavelengths of the nonabsorbed light radiation that is reflected. b) The characteristic color is determined by the distribution of wavelengths of the nonabsorbed light radiation that is transmitted through the material. c) The characteristic color is determined by the distribution of wavelengths of the reflected light radiation that is absorbed. d) The characteristic color is determined by the distribution of x-rays in the x-ray spectrum.
a) The characteristic color is determined by the distribution of wavelengths of the nonabsorbed light radiation that is reflected.
"Coring," which represents a form of non-equilibrium solidification, results in variations in the composition of a solidifying alloy. Coring occurs because of rapid solidification (i.e., the alloy solidifies faster than diffusion can occur to equilibrate composition). Is this true or false? a) True b) False
a) True
For precipitation hardening, the solution heat treatment consists of (1) heating the alloy to a temperature such that all solute atoms are dissolved to form a single-phase solid solution, and (2) quenching to produce a nonequilibrium supersaturated solid solution.. Is this true or false? a) True b) False
a) True
The equation for determining the packing factor of a cell with only one type of atom is _______________. a. (number of atoms/cell)((4π/3)(radius on atom)3) b. (number of atoms/cell)((1π/3)(radius on atom)3) c. (number of atoms/cell)((4π/3)(radius on atom)2) d. (number of atoms/cell)((2π/3)(radius on atom)3)
a. (number of atoms/cell)((4π/3)(radius on atom)3)
Covalently bonded materials frequently have complex structures in order to satisfy the directional restraints imposed by the bonding. a. True b. False
a. True
The direction of a Miller indices and its multiple are the same. a. True b. False
a. True
Materials with high binding energy have also have __________ strength and __________ melting temperature. a. high, high b. low, high c. low, low d. high, low
a. high, high
Which of the following choices includes the names for all three cubic crystal Bravais lattices. a. simple cubic, face-centered cubic, body-centered cubic b. simple cubic, corner-centered cubic, body-centered cubic c. complex cubic, face-centered cubic, inverse-centered cubic d. complex cubic, face-centered cubic, body-centered cubic
a. simple cubic, face-centered cubic, body-centered cubic
Consider a metal that has a face-centered cubic (FCC) crystal structure. If that metal has an atomic radius of 0.137 nm, calculate the volume of its unit cell in m^3.
a=2r√2=2√2(0.137*10^-9 m) = 3.875*10^-10 m V= a³ = 5.818*10^-29 m³
Materials that can have more than one crystal structure are called polymorphic or allotropic. The term _________ refers to pure elements with more that one crystal structure. The term ___________ is used for compounds with more that one crystal structure.
allotropic polymorphic
Oxidation occurs at the {cathode or anode}; reduction at the {anode or cathode}.
anode, cathode
What is the atomic number of an atom? a. The atomic number of an atom is the sum value of protons and neutrons per atom. b. The atomic number of an atom is the number of protons per atom. c. The atomic number of an atom is the number of electrons per atom. d. The atomic number of an atom is the number of neutrons per atom.
b. The atomic number of an atom is the number of protons per atom.
Density is a ratio of ____ a. Pounds/Area b. Weight/Volume c. Time/Distance d. Volume/Weight
b. Weight/Volume
Crystal structures with ions must have ____________. a. a positive charge b. electrical neutrality c. a negative charge d. a 2+ charge
b. electrical neutrality
In an extrinsic p-type semiconductor, the concentration of electrons is _________ the concentration of holes. a) Greater than b) Equal to c) Less than
c) Less than
A eutectic reaction involves which of the following phases? a) Three solid b) One liquid and one solid c) One liquid and two solids d) Two liquids and one solid
c) One liquid and two solids
The solvent is an element or compound that is present in ________. a) A minor concentration b) An intermediate amount c) The greatest amount d) None of these
c) The greatest amount
These materials have good electrical and thermal conductivities, relatively high strength, high stiffness, ductility or formability, and shock resistance. These materials are particularly useful for structural or load-bearing applications. a. Polymers b. Semiconductors c. Metals and Alloys d. Ceramics
c. Metals and Alloys
These materials are typically organic materials, are typically good electrical and thermal insulators, and generally have very good strength-to-weight ratios. They are generally not suitable for high temperature applications. a. Semiconductors b. Ceramics c. Polymers d. Metals and Alloys
c. Polymers
What is the relationship between a Miller indices value and its negative value? a. There is no relation between the vectors b. The vectors have the same magnitude, but point in congruent directions of each other. c. The vectors represent the same line, but point in opposite directions. d. The vectors represent the same line and point in the exact same direction.
c. The vectors represent the same line, but point in opposite directions.
A lattice is a collection of points named ____________, which are arranged in a periodic pattern so the surroundings of each point in the lattice are identical. a. assumed points b. location points c. lattice points d. formation points
c. lattice points
In ionic bonds the atom that contributes an electron and has a positive charge as a result is called the ______ . The atom in iconic bonding that accepts an electron and has a negative charge as a result is called the ______ .
cation, anion
A Frenkel defect is composed of which of the following? a) A cation interstitial and an anion interstitial b) An anion interstitial and an anion vacancy c) A cation vacancy and an anion vacancy d) A cation interstitial and a cation vacancy
d) A cation interstitial and a cation vacancy
Once a system is at a state of equilibrium, a shift from equilibrium may result by alteration of which of the following? a) Pressure b) Composition c) Temperature d) All of the above e) None of these
d) All of the above
In an extrinsic n-type semiconductor, where is the Fermi level located? a) In the middle of the band gap b) Inside the conduction band c) Inside the valence band d) Inside the band gap but just below the conduction band e) Inside the band gap but just above the valence band
d) Inside the band gap but just below the conduction band
A solidus line separates which of the following phase fields? a) α and α + β b) Liquid and liquid + α c) Liquid + α and α + β d) α and liquid + α
d) α and liquid + α
**This material is generally an inorganic nonmetallic material, does not conduct heat well and must be heated to very high temperatures before melting. Also this material is very strong and hard, but also very brittle. a. Polymers b. Metals and Alloys c. Composites d. Ceramic
d. Ceramic
Metallic, covalent, and ionic bonds are known as ________? a. secondary bonds b. executive bonds c. tertiary bonds d. primary bonds
d. primary bonds
X-rays that strike certain crystallographic planes at specific angles are reinforced rather than annihilated. This phenomenon is called __________.
diffraction
The fluorite structure is _______________ Bravais lattice.
face-centered cubic
FCC metal
r=√2/4*a⁰ a=2r√2
BCC metal
r=√3/4*a₀ a=4r/√3
