12.4: Phase Changes
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MAIN IDEA: _________ changes when _________ is
________ or _________.
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Most substances exist in _________ states
depending on ___________ and ______________.
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Referred to as __________ ____________
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How many phases can be observed in a glass of
ice water?
Phase Changes That Require Energy
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One phase can change to another when __________ is
added or removed from a system.
Phase Changes
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Melting
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What happens to ice cubes in water?
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Ice ____ because water is at ______ _______________.
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_______ flows from _______ to _______.
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Heat is the __________ of _________ from an object at
_______ temperature to an object of ________ temperature.
Energy absorbed by ice disrupts _________ ________ in ice
crystal, allowing water molecules to _______ ______ and enter
the _________ phase.
Phase Changes
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Melting
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Amount of _________ required to melt a solid depends
on the _________ of the ___________ keeping the
particles together.
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_________ ________ of a solid is the temperature at
which the __________ holding its _________ ________
together are _________ and it becomes a _______.
Phase Changes
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Vaporization
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Particles that _______ from the ________
phase enter the ____ phase.
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Gas phase for substances that are
normally ________ at _________
temperature is called ________.
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___________ is the process by which a
_______ changes to a _____ or
_________.
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When vaporization occurs only at the
___________ of of a _________, the
process is called ________________.
Phase Changes
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Boiling
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_________ _________ is the
temperature at which the
_________ _________ of
_________ equals the
________________ pressure.
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At the boiling point,
molecules have enough
_________ to ____________.
Phase Changes
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Sublimation
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Process by which a ___________ changes directly to a
________ without first becoming a ___________.
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What are some examples of sublimation?
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A:
Phase Changes
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What do melting, vaporization, boiling, and sublimation
have in common?
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These phase changes ___________ ___________.
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_______________ reactions.
Phase Changes
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Freezing
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________ is removed as substances change from ________
to ________ form, causing the molecules to lose ________
____________ and decrease __________.
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When enough energy is lost, ________ keep the
molecules in ___________ positions.
Freezing is the _____________ of melting.
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Freezing point is the ______________ at which a
__________ is converted to a ____________ ________.
Phase Changes
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Condensation
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When water vapor molecules lose ___________, their
___________ decreases.
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Causes the formation of ___________ ___________ and the
release of __________.
The process by which a ______ or ________ becomes _________
is called _____________.
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Reverse of _______________.
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Always involves the _________ of ___________ ___________.
Phase Changes
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Deposition
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Process by which a substance changes from a ______
or _______ to a ______ without first becoming a
________.
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Reverse of _____________.
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Phase Changes
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What do freezing, condensation, and deposition have in
common?
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These phase changes __________ ___________.
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_______________ reactions.
Phase Diagrams
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Two __________ control the _________ of a substance.
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______________ & ____________
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Variables have ____________ effects on a substance.
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Phase Diagrams
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Phase Diagrams
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______ of ____________ vs
_____________ that shows at
which _________ a
substance exists under
different _______________ of
temperature and pressure.
Phase Diagrams
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Phase Diagrams
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______ phases coexist at
points along each _______.
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Yellow = ______ water &
water ______ (_____).
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Blue = ______ & water
________.
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Red = _______ & ________
Phase Diagrams
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Phase Diagrams
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_________ ________ is the
point on a phase diagram
that represents the
_____________ and
_____________ at which
____________ phases of a
substance can ___________. •
All ________ phase changes
can occur at the triple point.
Phase Diagrams
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Phase Diagrams
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Triple point is the point on a
phase diagram that
represents the temperature
and pressure at which three
phases of a substance can
coexist. (POINT “A”)
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All six phase changes can
occur at the triple point.
Phase Diagrams
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Phase Diagrams
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_________ _________
indicates the critical
___________ and
____________ above which
_________ cannot exist as a
__________.