MTL 200 ASSESSMENT STUDY SHEET 2026
ACCURATE ANSWERS VERIFIED
⫸ What is the Pauli Exclusion Principle? Answer: each electron state
can hold no more than two electrons which must have opposite signs
⫸ What is the Stable Electron Configuration? Answer: the state
within the outermost shell completely filled (ex. inert gases: He, Ne,
Ar, etc)
⫸ What is bonding energy? Answer: the energy required to separate
two atoms that are chemically bonded to an infinite distance (units:
kJ/mol or eV/atom)
⫸ Which kinds of bonds are nondirectional? Which are directional?
Answer: Nondirectional: ionic bonding, metallic bonding
Directional: covalent bonding
⫸ What is the difference between directional and nondirectional
bonding? Answer: Nondirectional: magnitude of the bond is equal in
all directions around an ion
Directional: atoms need to be in a specific orientation
⫸ What is the relationship between the unit cell edge length and the
atomic radius for FCC crystal structures? Answer: a = unit cell edge
length
,R = atomic radius
a = 2Rsqrt(2)
⫸ How many atoms are in the FCC structure? Answer: 4 atoms
⫸ What is the relationship between the unit cell edge length and the
atomic radius for BCC crystal structures? Answer: a = (4R)/sqrt(3)
⫸ How many atoms are in the BCC structure? Answer: 2 atoms
⫸ What is the relationship between the unit cell edge length and the
atomic radius for HCP crystal structures? Answer: a = 2R
⫸ How many atoms are in the HCP structure? Answer: 6 atoms
⫸ What is the formula for volume of HCP unit cell in terms of a and
c? Answer: V = (3ca^2sqrt(3))/2
⫸ What are the coordination numbers of FCC, BCC, and HCP
structures? Answer: FCC: 12
BCC: 8
HCP: 12
⫸ What are the APF of FCC, BCC, and HCP structures? Answer:
FCC: 0.74 or 74%
, BCC: 0.68 or 68%
HCP: 0.74 or 74%
⫸ What is the formula for the volume of 4 atoms in FCC? Answer:
V=4*(4/3)(piR^3)
⫸ What is polymorphism? What is it called for elements? Answer: -
the phenomenon of a solid material existing in more than one form of
crystal structure.
- for elements, it is called allotropy
⫸ What coordinate form do you use for crystallographic directions
for cubic structures, hexagonal structures and for a family of
equivalent directions? Answer: Cubic structures: [UVW]
Hexagonal structures: [uvtw]
Family of equivalent directions: <uvw> <uvtw>
⫸ How do you convert [UVW] to [uvtw]? Answer: u = (1/3)(2U-V)
v = (1/3)(2V-U)
t = -(u+v)
w=W
⫸ What is the formula for linear density (LD)? Answer: LD = (# of
atoms centered on a direction vector)/(length of direction vector)
ACCURATE ANSWERS VERIFIED
⫸ What is the Pauli Exclusion Principle? Answer: each electron state
can hold no more than two electrons which must have opposite signs
⫸ What is the Stable Electron Configuration? Answer: the state
within the outermost shell completely filled (ex. inert gases: He, Ne,
Ar, etc)
⫸ What is bonding energy? Answer: the energy required to separate
two atoms that are chemically bonded to an infinite distance (units:
kJ/mol or eV/atom)
⫸ Which kinds of bonds are nondirectional? Which are directional?
Answer: Nondirectional: ionic bonding, metallic bonding
Directional: covalent bonding
⫸ What is the difference between directional and nondirectional
bonding? Answer: Nondirectional: magnitude of the bond is equal in
all directions around an ion
Directional: atoms need to be in a specific orientation
⫸ What is the relationship between the unit cell edge length and the
atomic radius for FCC crystal structures? Answer: a = unit cell edge
length
,R = atomic radius
a = 2Rsqrt(2)
⫸ How many atoms are in the FCC structure? Answer: 4 atoms
⫸ What is the relationship between the unit cell edge length and the
atomic radius for BCC crystal structures? Answer: a = (4R)/sqrt(3)
⫸ How many atoms are in the BCC structure? Answer: 2 atoms
⫸ What is the relationship between the unit cell edge length and the
atomic radius for HCP crystal structures? Answer: a = 2R
⫸ How many atoms are in the HCP structure? Answer: 6 atoms
⫸ What is the formula for volume of HCP unit cell in terms of a and
c? Answer: V = (3ca^2sqrt(3))/2
⫸ What are the coordination numbers of FCC, BCC, and HCP
structures? Answer: FCC: 12
BCC: 8
HCP: 12
⫸ What are the APF of FCC, BCC, and HCP structures? Answer:
FCC: 0.74 or 74%
, BCC: 0.68 or 68%
HCP: 0.74 or 74%
⫸ What is the formula for the volume of 4 atoms in FCC? Answer:
V=4*(4/3)(piR^3)
⫸ What is polymorphism? What is it called for elements? Answer: -
the phenomenon of a solid material existing in more than one form of
crystal structure.
- for elements, it is called allotropy
⫸ What coordinate form do you use for crystallographic directions
for cubic structures, hexagonal structures and for a family of
equivalent directions? Answer: Cubic structures: [UVW]
Hexagonal structures: [uvtw]
Family of equivalent directions: <uvw> <uvtw>
⫸ How do you convert [UVW] to [uvtw]? Answer: u = (1/3)(2U-V)
v = (1/3)(2V-U)
t = -(u+v)
w=W
⫸ What is the formula for linear density (LD)? Answer: LD = (# of
atoms centered on a direction vector)/(length of direction vector)
