CEM 141 EXAM 3 EXAM WITH
CORRECT QUESTIONS AND ANSWERS
2025
change of state from solid -> liquid -> gas ________ energy - CORRECT-ANSWERSrequires
energy needed to phase change from solid --> liquid --> gas comes from: - CORRECT-
ANSWERSthe surroundings
when phases change from solid --> liquid --> gas, interactions are _______ between molecules -
CORRECT-ANSWERSovercome
change of state from gas --> liquid --> solid ______ energy - CORRECT-ANSWERSreleases
what happens to the energy from a phase change from gas --> liquid --> solid? - CORRECT-
ANSWERSreleased to surroundings
when phases change from gas --> liquid --> solid, interactions are _______ between molecules -
CORRECT-ANSWERSformed
,what happens when a substance melts? - CORRECT-ANSWERSthe 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: - CORRECT-ANSWERSthe strength of the
attractive interactions between particles
which is stronger?? covalent bond/LDF - CORRECT-ANSWERScovalent bond
in a covalent bond, what is formed? - CORRECT-ANSWERSa new molecule
what is a LDF caused by? - CORRECT-ANSWERSfluctuating charge distribution
covalent bonds are the sharing of: - CORRECT-ANSWERSvalence electrons
LDF's increase with.... - CORRECT-ANSWERSthe size of electron cloud
covalent bonds are caused by: - CORRECT-ANSWERSattraction between electrons of one
atom and the nucleus of another
,LDFs are present where??? - CORRECT-ANSWERSbetween all molecular species
is it hard or easy to predict covalent bond strength? - CORRECT-ANSWERShard
when are covalent bonds present? - CORRECT-ANSWERSwhen atomic orbitals interact
constructively
covalent bonds are located: - CORRECT-ANSWERSbetween molecules/networks
LDFs occur between: - CORRECT-ANSWERSseparate molecules
diamond has a high/low melting point??? - CORRECT-ANSWERShigh
graphite has a high/low melting point?? - CORRECT-ANSWERShigh
diamond is hard/soft? - CORRECT-ANSWERShard
graphite is hard/soft? - CORRECT-ANSWERSsoft
diamond's physical properties - CORRECT-ANSWERSbrittle, translucent
, diamond does/does not conduct electricity?? - CORRECT-ANSWERSdoes not
graphite's physical properties - CORRECT-ANSWERSslippery, shiny, grey
graphite does/does not conduct electricity? - CORRECT-ANSWERSdoes
in diamond, each carbon forms how many bonds to how many carbons??? - CORRECT-
ANSWERS4 bonds to 4 identical carbons
in diamond, the bonds between carbons arrange themselves towards: - CORRECT-
ANSWERSthe corners of a 4-sided figure (tetrahedron)
what is the C-C-C bond angle in diamond? - CORRECT-ANSWERS109°
what model of bonding is used to explain the bonding in carbon? - CORRECT-
ANSWERSValence Bond Theory
Valence Bond Theory - CORRECT-ANSWERSatomic orbitals overlap to form bonds
how are bonds often shown in the valence bond theory? - CORRECT-ANSWERSas "sticks"
CORRECT QUESTIONS AND ANSWERS
2025
change of state from solid -> liquid -> gas ________ energy - CORRECT-ANSWERSrequires
energy needed to phase change from solid --> liquid --> gas comes from: - CORRECT-
ANSWERSthe surroundings
when phases change from solid --> liquid --> gas, interactions are _______ between molecules -
CORRECT-ANSWERSovercome
change of state from gas --> liquid --> solid ______ energy - CORRECT-ANSWERSreleases
what happens to the energy from a phase change from gas --> liquid --> solid? - CORRECT-
ANSWERSreleased to surroundings
when phases change from gas --> liquid --> solid, interactions are _______ between molecules -
CORRECT-ANSWERSformed
,what happens when a substance melts? - CORRECT-ANSWERSthe 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: - CORRECT-ANSWERSthe strength of the
attractive interactions between particles
which is stronger?? covalent bond/LDF - CORRECT-ANSWERScovalent bond
in a covalent bond, what is formed? - CORRECT-ANSWERSa new molecule
what is a LDF caused by? - CORRECT-ANSWERSfluctuating charge distribution
covalent bonds are the sharing of: - CORRECT-ANSWERSvalence electrons
LDF's increase with.... - CORRECT-ANSWERSthe size of electron cloud
covalent bonds are caused by: - CORRECT-ANSWERSattraction between electrons of one
atom and the nucleus of another
,LDFs are present where??? - CORRECT-ANSWERSbetween all molecular species
is it hard or easy to predict covalent bond strength? - CORRECT-ANSWERShard
when are covalent bonds present? - CORRECT-ANSWERSwhen atomic orbitals interact
constructively
covalent bonds are located: - CORRECT-ANSWERSbetween molecules/networks
LDFs occur between: - CORRECT-ANSWERSseparate molecules
diamond has a high/low melting point??? - CORRECT-ANSWERShigh
graphite has a high/low melting point?? - CORRECT-ANSWERShigh
diamond is hard/soft? - CORRECT-ANSWERShard
graphite is hard/soft? - CORRECT-ANSWERSsoft
diamond's physical properties - CORRECT-ANSWERSbrittle, translucent
, diamond does/does not conduct electricity?? - CORRECT-ANSWERSdoes not
graphite's physical properties - CORRECT-ANSWERSslippery, shiny, grey
graphite does/does not conduct electricity? - CORRECT-ANSWERSdoes
in diamond, each carbon forms how many bonds to how many carbons??? - CORRECT-
ANSWERS4 bonds to 4 identical carbons
in diamond, the bonds between carbons arrange themselves towards: - CORRECT-
ANSWERSthe corners of a 4-sided figure (tetrahedron)
what is the C-C-C bond angle in diamond? - CORRECT-ANSWERS109°
what model of bonding is used to explain the bonding in carbon? - CORRECT-
ANSWERSValence Bond Theory
Valence Bond Theory - CORRECT-ANSWERSatomic orbitals overlap to form bonds
how are bonds often shown in the valence bond theory? - CORRECT-ANSWERSas "sticks"
