Gases Day 3
Standard 4:The kinetic molecular
theory describes the motion of atoms
and molecules and explains the
properties of gases.
Objective
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I can explain gas
properties using the
kinetic molecular
theory of gases.
Agenda
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Catalyst
HW Review
Under Pressure!
KMT Memory Game
Exit Slip
Catalyst
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Discuss: Is there any scientific
basis for the assertion that
“whoever smelt it dealt it?”
Why or why not?
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Take out last night’s HW to be
stamped. Turn in your poster if
you have not already.
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Homework: Skim pp.
423 – 432 in order to
answer p. 432 # 1-4
Homework Review
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1. The characteristic of gases that makes them
different from liquids or solids is their relatively
large intermolecular distances. The distance
between gas molecules is very large.
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3. When a gas is compressed the gas particles
are pushed closer together.
Homework Review
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7. A gas’s ability to fill a container is
different from that of a liquid or a solid
because a gas fills the entire container.
Liquids take on the shape of the bottom of
a container but do not spread out to fill it.
Solids maintain their own shape.
Homework Review
11. The kinetic-molecular theory can explain why atmospheric
pressure is greater at lower altitudes than at higher altitudes if we
remember that gravity acts on gas particles. The force of gravity pulls
more gas particles towards the earth’s surface. Because there are
more gas particles in any given space at lower altitudes, there are more
collisions of the particles against surfaces and therefore higher
pressure. Conversely, as you move to high altitudes, there are less
gas particles causing less collisions and therefore less pressure.
Under Pressure!
Reading Activity!
Work quietly with a
partner.
Be ready to learn: What is air
pressure? How do we measure
pressure?
If you finish early, play the KMT
memory game!
Homework
Finish any article questions or worksheet
problems.
 Skim pp. 423-432 Do problems pp. 432 #14 (additional resources on class website)
 Optional: Flashcards: pascals, mm Hg,
atmospheres, vapor pressure, Boyle’s Law,
Charles’s Law, Gay-Lussac’s Law,
Avogadro’s Law
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Exit Slip Answers
1.
Ms. Boon drove over a nail, punching a hole
in her tire.
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What happened to the air that was in the tire?
 It
escaped.
Did the air pressure in the tire increase or
decrease? The pressure decreased.
 Why? There were fewer gas molecules to hit the
side of the tire.
2. Eduardo blew up a balloon so big that it popped.
Why did the balloon pop?
The pressure the air exerted on the balloon became
too much for the plastic.
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