Transcript Do Now:(on Edmodo)

Do Now:(on Edmodo)
In your NOTEBOOK: Write
down the question and answer.
What are your personal experiences
with Solids, Liquids and Gases?
 All of your personal experiences are at a “sensory
level”
 Observe matter and the changes through your 5
senses.
 Making observations is the first step in “doing
science”
 To explain observations  develop a theory
Scientific theory – explains observations and
can be used to predict outcomes.
Solids, Liquids and Gases
 What do you know about solids, liquids and
gases?
 What is the difference between the different
particles?
Solids, Liquids, and Gases
Solids
• Definite shape
• Rigid structure
• Particles
packed tightly
together
• Vibrate in
place
• Cannot move
past each other
Liquids
Gases
Solids, Liquids, and Gases
Solids
Liquids
• Definite shape • Flows
• Rigid structure • Takes the shape
• Particles
of the container
packed tightly • Particles are
together
mobile, can
• Vibrate in
move past each
place
other but can’t
• Cannot move
move too far
past each other apart
Gases
Solids, Liquids, and Gases
Solids
Liquids
Gases
• Definite shape • Flows
• No definite
• Rigid structure • Takes the shape
shape
• Particles
of the container • Particles not
packed tightly • Particles are
strongly
together
mobile, can
attracted to
• Vibrate in
move past each
each other
place
other but can’t • Particles are
• Cannot move
move too far
VERY far apart
past each other apart
• Move at high
speeds in
straight lines
Kinetic Molecular Theory (KMT)
 Gas molecules move because of how much
kinetic energy they have
 Kinetic energy (KE) – energy of motion
 Depends on an object’s mass and velocity
KMT - Behavior of gases
 Contains postulates – accepted statements used
as a basis for developing explanations
1. Gases consist of tiny particles (molecules) that
are great distances apart
2. Gas molecules are in constant, random motion.
They collide and cause gas pressure
3. Collisions are elastic
 Elastic – when molecules collide, total
energy is not lost
4. As temperature increases, the average KE
increases.
5. Gas molecules only interact during collisions
The KMT is used to explain gas behaviors. If a gas
follows these rules… Called “Ideal Gas”
Practice problems
1. Decide which of these four gas variables—volume,
temperature, pressure, and number of molecules—best
matches each of the following, and explain each
choice.
 the number of super-bounce balls in the box
 the size of the box
 the vigor with which you shake the box
 the number and force of collisions with the box
walls of the randomly moving super-bounce balls
2. How does each of the following changes relate to what
you have learned about gas behavior?
 The vigor of shaking and the number of super-bounce
balls remain the same, but the size of the box is
decreased.
 The size of the box and the number of super-bounce
balls remain the same, but the shaking becomes more
vigorous.
 The size of the box and the vigor of shaking are kept
the same, but the number of super-bounce balls is
increased.
3. Suggest another situation similar to those in Question 2
that can serve as an analogy for the behavior of
gases. Explain how the situation is analogous.
4. Describe your own analogy that might be useful
for modeling gas behavior.
 Identify features of your analogy that relate to
features of KMT and T-V-P relationships for
gases.
 Point out some key limitations of your analogy.