Materials Exam 1 questions well
answered already passed
The element with the lowest density and smallest atomic weight is which one of the following -
ANS ✔Hydrogen, because it is the first element on the periodic table
Which of the following bond types are classified as primary bonds (3) - ANS ✔Covalent, ionic,
and metallic....
Not Van or hydrogen
Metals are characterized by which one of the following bonding types - ANS ✔Metallic, think of
a good explanation
In general, metals are characterized by which of the following properties (3) - ANS ✔High
electrical conductivity, high hardness, high thermal conductivity, opaque and reflective
How many atoms are there in the BCC unit cell? - ANS ✔2, 1 center and 8 corner which each is
1/8
1+1/8 = 2
How many atoms are there in the FCC unit cell - ANS ✔4, 6 sides each at 1/2 + 8 corner which is
1/8
How many atoms are there in teh HCP unit cell? - ANS ✔6, 3 in center, 2 center top and bottom
each at 1/2 and 12 outer each at 1/6
, The coordination number and the atomic packing factor for the HCP crystal structure are the
same as for FCC - ANS ✔True
The atomic packing factor for the BCC crystal structure is - ANS ✔0.68
It is possible to produce a perfect crystalline solid that does not contain any vacancies? - ANS
✔False, Can't make perfect crystals
Which of the following are point defects in a crystal lattice structure - ANS ✔Interstitials and
Vacancy
Grain boundaries are an example of which one of the following types of crystal structure defects
- ANS ✔Area or interface defects
In materials exhibiting mixed bonding, the percent ionic character between two elements A and
B depends on - ANS ✔electronegativity, need explanation
The X-ray diffraction technique is used to determine - ANS ✔Crystal structure and interplanar
spacing
The equilibrium number of vacancies N(v) for a given quantity of material depends or increases
with temperature according to - ANS ✔Exponentially, it is an exponential equation
Secondary bonding (examples and difference between primary) - ANS ✔Van der Wall, dipole-
dipole, and polar
Primary bonds are hard to break while secondary is easier
Ionic (examples and difference between secondary) - ANS ✔Bond between a positive and
negative and they trade electrons, metal and nonmetal (nondirectional)
answered already passed
The element with the lowest density and smallest atomic weight is which one of the following -
ANS ✔Hydrogen, because it is the first element on the periodic table
Which of the following bond types are classified as primary bonds (3) - ANS ✔Covalent, ionic,
and metallic....
Not Van or hydrogen
Metals are characterized by which one of the following bonding types - ANS ✔Metallic, think of
a good explanation
In general, metals are characterized by which of the following properties (3) - ANS ✔High
electrical conductivity, high hardness, high thermal conductivity, opaque and reflective
How many atoms are there in the BCC unit cell? - ANS ✔2, 1 center and 8 corner which each is
1/8
1+1/8 = 2
How many atoms are there in the FCC unit cell - ANS ✔4, 6 sides each at 1/2 + 8 corner which is
1/8
How many atoms are there in teh HCP unit cell? - ANS ✔6, 3 in center, 2 center top and bottom
each at 1/2 and 12 outer each at 1/6
, The coordination number and the atomic packing factor for the HCP crystal structure are the
same as for FCC - ANS ✔True
The atomic packing factor for the BCC crystal structure is - ANS ✔0.68
It is possible to produce a perfect crystalline solid that does not contain any vacancies? - ANS
✔False, Can't make perfect crystals
Which of the following are point defects in a crystal lattice structure - ANS ✔Interstitials and
Vacancy
Grain boundaries are an example of which one of the following types of crystal structure defects
- ANS ✔Area or interface defects
In materials exhibiting mixed bonding, the percent ionic character between two elements A and
B depends on - ANS ✔electronegativity, need explanation
The X-ray diffraction technique is used to determine - ANS ✔Crystal structure and interplanar
spacing
The equilibrium number of vacancies N(v) for a given quantity of material depends or increases
with temperature according to - ANS ✔Exponentially, it is an exponential equation
Secondary bonding (examples and difference between primary) - ANS ✔Van der Wall, dipole-
dipole, and polar
Primary bonds are hard to break while secondary is easier
Ionic (examples and difference between secondary) - ANS ✔Bond between a positive and
negative and they trade electrons, metal and nonmetal (nondirectional)
