Part I: Energy Transport
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Examine the carbon dioxide (CO2) cylinder. Describe the cylinder:
Demo 1 - The instructor will punch a hole in the cylinder.
What is happening, and how is the cylinder changing?
Based on these observations:
As a gas expands it warms / cools (Circle one).
As you compress a gas, we would expect it to warm / cool (Circle one).
Water occurs in three phases – solid (ice), liquid (water) and gas (water vapor)
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What do you have to do to turn ice into water?
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Which phase has the highest energy? Lowest Energy? (Use 1 for the highest energy and
Solid ____ Liquid ___ Gas ___
3 for the lowest energy)
Solid to liquid – Melting
Liquid to solid – Freezing
Why is the ocean salty?
Phase Changes
Liquid to gas – Vaporization
Gas to liquid – Condensation
Solid to gas – Sublimation
Gas to solid – Deposition
Part II: Convection and Precipitation
Hot air rises, but as it rises, the pressure
decreases!
Will a rising gas expand or compress?
The Andes Mountains in South America
are very tall and are on the coast and
create a rain shadow.
This cause the gas to warm / cool? (Circle
one).
Which is more dense, warm or cool air?
(Circle one).
Which heats up faster: land or water?
Which cools off faster: land or water?
Critical Thinking: How does this form?
Sea Breeze:
In the day, air blows from the water
towards the land.
In the evening, air blows from the land
towards the water.
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Part III: Formation of Clouds
What is a cloud made of?
Demo 2 – Cloud in a bottle (With and without the smoke)
Observe the bottle with and without the smoke.
When did the cloud form? Before or after the pressure was released? (Circle one).
Why might a pressure drop help cloud formation? (Think about Demo 1)
Did the presence of the smoke effect cloud formation? Yes / No (Circle one).
What do you think happened?
Cloud condensation nuclei (CCNs , also known as cloud seeds) are very small particles
(about 100 times smaller than a human hair!) that cloud drops form on. Without a particle,
the water vapor has no place to become a liquid on!
What other particles might help form clouds besides smoke from a fire? List a few!
Part IV: Particle Creation and Air Pollution
Some particles get into the atmosphere directly. Name a few possible sources:
Particles can also form spontaneously from gases in the air around us.
This happens when complex molecules start to stick together!
Demo 3 – Ozone and an Orange Peel
Examine your orange peel and discuss within the group your observations.
Orange peels have a very strong smell. This is because they contain
small, complex molecules that can evaporate into the air. One of these is
called limonene (shown on the right).
When you smell the orange, you are breathing in these molecules!
Now examine your glass flask. With the help of your instructor, shine your
laser through. What do you see?
Before class, the glass flask was filled with a gas called ozone.
Ozone at the top of the atmosphere blocks dangerous UV light from the sun.
Ozone at the surface, however, can be a hazardous pollutant!
In your group, rough up your orange peel and quickly drop it into the glass flask and seal it.
With your instructor again, shine your laser through. What do you observe happening?
Ozone is highly reactive, and makes the orange peel molecules more “sticky”.
When they start to stick together, you get new particles!
Will this only work with orange peels? What other things could emit complex (smelly)
molecules?
Ozone pollution is very common in cities and congested areas. Would you expect this sort of
thing to happen in a polluted environment? What would you call the particle haze? (hint:
think of Los Angeles)