Quiz Review Flashcards
There are several classes of materials available for engineers. One of the major classes is polymers. What is the name of one if the other major classes weve discussed in class?
Ceramics or metals
The bohr model of atomic arrangement is currently the most adbanced model we currently have.
False
Write the possible sequence of values that the “Azimuthal Quantum” number I could take:
0, 1, 2, 3
s, p, d, f
Which quantum number relates to the size of an atom:
n
The position of electrons has an influence on the type of bonding that can occur between neighboring atoms:
True
What is the name of a positively charged ion?
Cation
In general, the higher the bond force between atoms then the higher the ____ temperature of the substance
Melting
What type of a bond results from the sharing of valence electrons
Covalent
Consider teo elements. Element A has the highest value of n=2, while element B has the highest value n=3. If both elements from a BCC structure in which case would you expect the BCC lattice parameter to be smaller?
Element B
Consider an atom which is not at its equilibrium state. Specifically the atom has more protons than neutrons (with respect to its equilibrium state) in that case the atom can be called an:
Isotope
Chlorine has an eectron configuration of 1s^2 2s^2 2p^6 3s^2 3p^5. What is the value of the principal quantum number
3
What is the name of a negatively charged ion?
Anion
When two elements bond an electropositive element:
Donates an electron
The “pauli exclusion principle” tells us that two electrons traveling in the same orbit around a nucleus will have opposite spin:
True
Consider two elements. Element A has the highest value of n =2 while element B has the highest value n =3. If both elements form a FCC structure in which case would you expect the FCC lattice parameter to be bigger
Element B
Which quantum njmber relates to the shape of the trajectory an electron takes while orbiting a nucleus
l
How many neutrons are present in a neutral silicon atom, which has an atomic number = 14, and has the following electron configuration 1s^2 2s^2 2p^6 3s^2 3p^2
14
The electron configuration for Bromine is 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^5
1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^4
Bromine is able to have several isotopes. This means that a Bromine isotope will have a:
Varying number of neutrons than an equilibrium Bromine atom
In “Van der Waals” bonding, a bond is created between two atoms due to:
Proximity of two atoms
The electron configuration for an atom of oxygen is 1s^2 2s^2 2p^4. Write the electron configuration for an O^-2 ion:
1s^2 2s^2 2p^2
What type of bonding would be expected for rubber (chemical formula C3H8)
Covalent Bonding
A positively charged ion is called
Cation
The higher thr melting temperature of a material, the greater the:
Bonding strength between atoms
When we talked about crystal structure in class we made an assumption that the individual atoms in a given unit cell were touching
True
In class, we’ve discussed that there are several ways to examine the structure of material. Which one of the following would be feasible to evaluate with a naked eye
Macrostructure
The electrons located in the outermost shell of an atom are often called _________ valence electrons.
Valence
Write the possible sequence of values that the principal quantum number n could take
1 2 3 4
K L M N
A negatively charged ion is called
Anion
The number of protons and neutrons in the nucleus is labeled using the following letter:
A
The electron configuration for an atom of Argon is 1s^2 2s^2 2p^6 3s^2 3p^6. How many electrons are in the valance shell?
8
What is the highest coordination number that can be achieved?
12
In general when bonds form the actual distance between two atoms is an equilibrium distance caused by the bond force. The bond force depends on the:
Attractive force between one nucleus and one electron cloud, and the repulsive force between two electron clouds
The electron configuration for an atom of oxygen is 1s^2 2s^2 2p^4. Write the electron configuration for an O^-2 ion
1s^2 2s^2 2p^2
Atoms that have full valence shells are often most reactive
False
FCC and BCC lattices both have a cubic crystal unit cell. As a result the lattice parameter of these two cubic systems in the same
False
In a given BCC crystal, the spacing between adjacent (110) planes is less than the spacing between adjacent (120) planes
False
Diffusion processes in gases and liquids are fast
True
Which material would have more grains per square inch: material A with an ASTM grain size number 2 or material B with ASTM grain size number 7.
Material B
The diffusion coefficient does not depend on the temperature at which a diffusion experiment is being conducted
False
In a given BCC crystal the spacing between adjacent 311 planes is less than the spacing between adjacent 020 planes.
True
The lattice parameter of a crystal give us information about the number of atoms in a unit cell
False
A dislocation is an example of a
Line defect
Ficks 1st law is applied to time dependent diffusion experiments
False
Which material would have more grains per square inch: material A with an ASTM grain size number 9 or material B with an ASTM grain size number 5
Material A
Diffusion processes in metals are fast
False
In a given FCC crystal the spcinng between adjacent 201 planes is less than the spacing between adjacent 110 planes
True
An edge dislocation can be created by applying what tk a material
Shear load
In a given FCC crystal the spacing between adjacent 132 planes is less than the soacing between adjacent 211 planes
True
All materials that have a cubic crystal structure will have the same lattice parameter value
False
In X ray diffraction experiments it is importa t that the x ray entering a material and the x eay exiting a material are in phase
True
What is the common format to designate a direction in the HCO system
[uvtw]
What is the name of the mechanical property corresponding to the following definition: “This property describes the deformation of a material at elevated temperatures
Creep
The term engineering stress and true stress can be used interchangeably
False
What is the name of a parameter which related the shear stress to shear strain
Shear modulus G
The higher the value of ____ the stiffer the material is!
Modulus of elasticity E
What is the name of the mechanical property corresponding to the following definition: “This property describes the ability of a material to retain shape and to stay deformed
Plasticity
When calculating strain the resulting value may be written without any units but it could also be written with in/in or cm/cm
True
What is the name of a parameter which related the strain in x direction to the strain in z direction
Poissons Ratio
When doing an ASTM test to obtain the stress strain diagram, as the test temperature increases then the value of E ____
Decreases
What is the name of the mechanical property corresponding to the following definition: “This property describes the ability of a material to absorb energy and resist soft of sometimes impact loading
Resilience
The term engineering strain and true strain can be used interchangeably
False
What is the name of a parameter which relates the tensile stress to the tensile strain
Youngs modulus E
During a tensile test, the response of the material transitions from the elastic to the plastic regime. The stress at which this occurs is called the______ stress
Yeild
What is the name of the mechanical property corresponding to the following definition “ This property describes the ability of a material to resist deformation when the material is loaded in the elastic region
Stiffness
Shear and torsion of a material cause its deformation. This deformation can be measured with angles. The units of these angles must be in degrees
False
During a hardness test, you can specify three parameters 1) Indenter, 2) Dwell time 3)______
Load/force
When considering fatigue as a possible condition that can lead to a material failure, which of the conditions mentioned below would be preferred ti minimize fatigue failure
Tensile cyclic loading
What is the name of the parameter that describes the fatigue behavior of a material after 10^7 cycles
Fatigue Strength
When considering the creep deformation of a material during which stage is the stress strain rate linear
Secondary
When a fracture propagates along a grain boundary it is called a ______ fracture
Intragranular
In which failure mode is the crack perpendicular to the loading direction
Brittle fracture
In general the bigger the radius of a crack tip, the higher stress concentration will develop near the crack tip
False
When creating an alloy with one of the constituents is caled a solvent the other is called the ______
Solute
When a ductile material breaks due to cyclic loading then the fracture surface has the characteristics of a
Brittle fracture
What is the name of a parameter that describes the number of cycles required to fracture a sample at a given load during fatigue cycling?
Fatigue life
During creep deformation of a material what is the name of the creep stage when the material fracture occurs
Tertiary
When a fracture propagates through across the grain boundaries it is called a _____ fracture
Transgranular
In which failure mode is there very little warning that fracture is imminent
Brittle Fracture
In general the longer the crack void defect in a material the greater a stress concentration will develop in the vicinity of the crack void defect
True
The term phase implies a material constituent that has a unique physical or ____ properties than the matrix material chemical
Fatigue typically occurs at a stress that is _____ the yeild strength of a given material
Below
What is the name used to designate a stress experienced during fatigue loading of a material and loading below this stress value is not sufficient to create a significant damage to the material and the material can operate for a long time
Fatigue limit
During creep what is the name of a parameter that indicates the time required to fracture a material at a given stress and temperature condition
Creep loading stress
When a fracture propagates along the grain boundaries it is called a ____ fracture
Intragranular
The cup and cone fracture usually occurs in which type of material
Ductile material
In general the maximum stress that develops near the tip of s crack void defect in a material is lower than the yeild stress of the material
False
The term phase implies chemical or _____ properties than the matrix material
Physical
During fatigue loading of a material the greater the average loading stress, then the ___ the expected lifespan of the component
Shorter
When examining a fracture surface of a material sample that failed due to cyclic loading, the fracture surface often bas ridges
True
When considering the creep deformation of a material during which stage in the strain rate linear?
Secondary
In which material would uou expect to see voids forming in the necking region during plastic deformation
Ductile material
In the immediate vicinity of a crack tip the stress concentration that evolves is often ____ than the UTS of the material
Greater
The amount of solute that can be dissolved in a matrix material is defined by the so-called ___ limit
Solubility
