What happens to substances when they change states of
mater?
Slide 3
o What happens to a puddle of water on a sunny day? o What
happens to ice on a warm day? o What happens to a pond in very cold
temperatures?
Slide 4
Science Standard 8.3.d: Students know the states of mater
depend on molecular motion. Science Standard 8.5.d: Students know
physical processes include freezing and boiling, in which a
material changes form with no chemical reaction.
Slide 5
melting: change in state from solid to liquid. melting point: a
characteristic temperature where melting occurs. freezing: change
from a liquid to a solid. vaporization: change from a liquid to a
gas. evaporation: vaporization that takes place only on the surface
of a liquid.
Slide 6
boiling: occurs when a liquid changes to a gas below and at the
surface. boiling point: the temperature at which a liquid boils.
condensation: the change in state from a gas to a liquid.
sublimation: occurs when the surface particles of solid gain enough
energy that they form a gas.
Slide 7
Melting Solid to Liquid When a substance melts, the particles
in the solid vibrate so fast that they break free from their fixed
positions (increase). A change from solid to liquid involves a gain
in thermal energy. Lets act like a solid!
Slide 8
Freezing Liquid to Solid When a substance freezes, the
particles in the liquid move so slowly that they begin to take on
fixed positions (decrease). The change from liquid to solid
involves a loss in thermal energy. Lets act like a solid!
Slide 9
Vaporization Liquid to Gas Vaporization that takes place only
on the surface of a liquid is called evaporation.
Slide 10
Boiling Liquid to Gas The boiling point of a substance depends
on the pressure of the air above it. The lower the pressure, the
less energy needed for the particles of the liquid to escape into
the air. Boiling point is a characteristic property of a
substance.
Slide 11
Condensation Gas to Liquid During condensation, the particles
in a gas lose enough thermal energy to form a liquid. Condensation
is the reverse of vaporization. Clouds in the atmosphere form due
to condensation.
Slide 12
Sublimation Solid to Gas Dry ice, or solid carbon dioxide, is
an example of compound that does not turn to liquid at normal
atmospheric pressures.
Slide 13
A beaker of ice at 10C was slowly heated to 110C. The graph
shows how the temperature of the water changed over time.
Slide 14
Temperature (C) on the y- axis, time (minutes) on the x-axis
Reading Graphs: What two variables are plotted on the graph?
Slide 15
The temperature is rising from 0C to 100C. Reading Graphs: What
is happening to the temperature of the water during segment C of
the graph?
Slide 16
Segment B: melting point of ice; segment D: boiling point of
water Interpreting Data: What does the temperature value for
segment B represent? For segment D?
Slide 17
Change from solid to liquid; change from liquid to gas Drawing
Conclusions: What change of state is occurring during segment B of
the graph? During segment D?
Slide 18
Draw a picture of melting. Draw a picture of freezing. Draw a
picture of sublimation.
Slide 19
Answer #1, 2, 6 Finish the worksheet.
Slide 20
HOMEWORK EXTENSION Write a detailed SUMMARY of the section and
complete the UNANSWERED QUESTIONS section of your notes. Choose two
of the remaining Depth & Complexity ICONS in your notes and
explain how they relate to this section.