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Michigan State University
CEM 141 CEM 141 Exam 3 Questions and
Answers 2026 Latest Update
change of state from solid -> liquid -> gas ________ energy Ans: requires
energy needed to phase change from solid --> liquid --> gas comes from:
Ans: the surroundings
when phases change from solid --> liquid --> gas, interactions are _______
between molecules Ans: overcome
change of state from gas --> liquid --> solid ______ energy Ans: releases
what happens to the energy from a phase change from gas --> liquid -->
solid? Ans: released to surroundings
when phases change from gas --> liquid --> solid, interactions are _______
between molecules Ans: formed
what happens when a substance melts? Ans: the interactions between the
particles have to be overcome -- so that they can remove relative to each
other (that's what allows a liquid to flow)
melting and boiling points provide an estimate of: Ans: the strength of the
attractive interactions between particles
which is stronger?? covalent bond/LDF Ans: covalent bond
in a covalent bond, what is formed? Ans: a new molecule
what is a LDF caused by? Ans: fluctuating charge distribution
covalent bonds are the sharing of: Ans: valence electrons
LDF's increase with.... Ans: the size of electron cloud
© 2026 All rights reserved
, 2 | Page
covalent bonds are caused by: Ans: attraction between electrons of one
atom and the nucleus of another
LDFs are present where??? Ans: between all molecular species
is it hard or easy to predict covalent bond strength? Ans: hard
when are covalent bonds present? Ans: when atomic orbitals interact
constructively
covalent bonds are located: Ans: between molecules/networks
LDFs occur between: Ans: separate molecules
diamond has a high/low melting point??? Ans: high
graphite has a high/low melting point?? Ans: high
diamond is hard/soft? Ans: hard
graphite is hard/soft? Ans: soft
diamond's physical properties Ans: brittle, translucent
diamond does/does not conduct electricity?? Ans: does not
graphite's physical properties Ans: slippery, shiny, grey
graphite does/does not conduct electricity? Ans: does
in diamond, each carbon forms how many bonds to how many carbons???
Ans: 4 bonds to 4 identical carbons
in diamond, the bonds between carbons arrange themselves towards: Ans:
the corners of a 4-sided figure (tetrahedron)
what is the C-C-C bond angle in diamond? Ans: 109°
what model of bonding is used to explain the bonding in carbon? Ans:
Valence Bond Theory
Valence Bond Theory Ans: atomic orbitals overlap to form bonds
how are bonds often shown in the valence bond theory? Ans: as "sticks"
© 2026 All rights reserved
Michigan State University
CEM 141 CEM 141 Exam 3 Questions and
Answers 2026 Latest Update
change of state from solid -> liquid -> gas ________ energy Ans: requires
energy needed to phase change from solid --> liquid --> gas comes from:
Ans: the surroundings
when phases change from solid --> liquid --> gas, interactions are _______
between molecules Ans: overcome
change of state from gas --> liquid --> solid ______ energy Ans: releases
what happens to the energy from a phase change from gas --> liquid -->
solid? Ans: released to surroundings
when phases change from gas --> liquid --> solid, interactions are _______
between molecules Ans: formed
what happens when a substance melts? Ans: the interactions between the
particles have to be overcome -- so that they can remove relative to each
other (that's what allows a liquid to flow)
melting and boiling points provide an estimate of: Ans: the strength of the
attractive interactions between particles
which is stronger?? covalent bond/LDF Ans: covalent bond
in a covalent bond, what is formed? Ans: a new molecule
what is a LDF caused by? Ans: fluctuating charge distribution
covalent bonds are the sharing of: Ans: valence electrons
LDF's increase with.... Ans: the size of electron cloud
© 2026 All rights reserved
, 2 | Page
covalent bonds are caused by: Ans: attraction between electrons of one
atom and the nucleus of another
LDFs are present where??? Ans: between all molecular species
is it hard or easy to predict covalent bond strength? Ans: hard
when are covalent bonds present? Ans: when atomic orbitals interact
constructively
covalent bonds are located: Ans: between molecules/networks
LDFs occur between: Ans: separate molecules
diamond has a high/low melting point??? Ans: high
graphite has a high/low melting point?? Ans: high
diamond is hard/soft? Ans: hard
graphite is hard/soft? Ans: soft
diamond's physical properties Ans: brittle, translucent
diamond does/does not conduct electricity?? Ans: does not
graphite's physical properties Ans: slippery, shiny, grey
graphite does/does not conduct electricity? Ans: does
in diamond, each carbon forms how many bonds to how many carbons???
Ans: 4 bonds to 4 identical carbons
in diamond, the bonds between carbons arrange themselves towards: Ans:
the corners of a 4-sided figure (tetrahedron)
what is the C-C-C bond angle in diamond? Ans: 109°
what model of bonding is used to explain the bonding in carbon? Ans:
Valence Bond Theory
Valence Bond Theory Ans: atomic orbitals overlap to form bonds
how are bonds often shown in the valence bond theory? Ans: as "sticks"
© 2026 All rights reserved
