MAT E 202 | QUESTIONS AND ANSWERS | 2026
UPDATE | WITH COMPLETE SOLUTION
metals & alloys Answer - strong, ductile, moderate elasticity, 1-3 valence e-,
sea of e-, non-directional bond
ceramics & glasses - covalent Answer - strong, brittle, high elasticity, poor
conductivity, sharing of valence e-, directional bond, electronegativity
ceramics & glasses - ionic Answer - strong, hard, brittle, high elasticity,
between cation & anion, requires e- transfer, non-directional bond
polymers - intrachain bonding Answer - covalent
polymers - interchain bonding Answer - weak van der Waals forces
types of stress Answer - tensile, compressive, shear
Bauschinger Effect Answer - mechanical properties cannot be assumed equal
under loading
elastic deformation (non-permanent) Answer - material will return to original
shape on unloading
, modulus of elasticity Answer - slope of elastic region, tangent to force curve at
r0, inversely proportional to CTE
microstructure (atomic) Answer - bonding between 2 atoms
microstructure (local) Answer - unit cell
microstructure (groups) Answer - crystalline/amorphous
covalent bond energy Answer - can be weak or strong
ionic bond energy Answer - high
metallic bond energy Answer - range
secondary bond energy Answer - weak
r0 Answer - equilibrium separation of atom centres at 0K, energy state where
attractive / repulsive forces are equal
E0 Answer - bond energy, energy required to separate 2 atoms an infinite
distance from each other, proportionate to melting temp.
plastic deformation (permanent) Answer - material doesn't return to original
shape on unloading
yield stress Answer - stress at which plastic deformation begins
UPDATE | WITH COMPLETE SOLUTION
metals & alloys Answer - strong, ductile, moderate elasticity, 1-3 valence e-,
sea of e-, non-directional bond
ceramics & glasses - covalent Answer - strong, brittle, high elasticity, poor
conductivity, sharing of valence e-, directional bond, electronegativity
ceramics & glasses - ionic Answer - strong, hard, brittle, high elasticity,
between cation & anion, requires e- transfer, non-directional bond
polymers - intrachain bonding Answer - covalent
polymers - interchain bonding Answer - weak van der Waals forces
types of stress Answer - tensile, compressive, shear
Bauschinger Effect Answer - mechanical properties cannot be assumed equal
under loading
elastic deformation (non-permanent) Answer - material will return to original
shape on unloading
, modulus of elasticity Answer - slope of elastic region, tangent to force curve at
r0, inversely proportional to CTE
microstructure (atomic) Answer - bonding between 2 atoms
microstructure (local) Answer - unit cell
microstructure (groups) Answer - crystalline/amorphous
covalent bond energy Answer - can be weak or strong
ionic bond energy Answer - high
metallic bond energy Answer - range
secondary bond energy Answer - weak
r0 Answer - equilibrium separation of atom centres at 0K, energy state where
attractive / repulsive forces are equal
E0 Answer - bond energy, energy required to separate 2 atoms an infinite
distance from each other, proportionate to melting temp.
plastic deformation (permanent) Answer - material doesn't return to original
shape on unloading
yield stress Answer - stress at which plastic deformation begins
