1. Investigation Four Date: 11/1/16
Title: “Investigation Four – Why do particles move?”
Students begin Investigation Four by reviewing some properties, behaviors, and characteristics of gases.

2. Challenge: How many different ways can you show what happens to air as it is heated and cooled?
Rules
Place nothing in the bottle
No crushing or folding of the bottle
Soap water stays in its own container
Share items nicely in your groups
Return everything in ready-to-go condition when done
Do not put your mouth on any science equipment/apparatus (Cooper)
I want you to think about this next question – I don’t want you to answer it right now, but what would happen if I heated or cooled the air in the bottle?
Imagine that you are going to show a class of fourth graders what happens to air when it is
heated and cooled. Try to find a good way to show what happens to a volume of air when it
is heated and when it is cooled.

3. Directions-working with your partner
Try several ways to demonstrate the heating and cooling of air.
In your science notebook, illustrate your favorite demonstration.
Below your labeled illustration, write an explanation that will help 4th graders understand what happens when air is heated and cooled.
Rules
Place nothing in the bottle
No crushing or folding of the bottle
Share items nicely in your groups
Return everything in ready-to-go condition when done…
These are the materials you will have to work with.
Show the materials
Show fill line on cup
Show hot and cold water stations
Give them time to work and record

4. Everything dry and clean!!
CLEAN UP
2 water bottles with caps
2 plastic cups
2 insulated cups
1 cup with soap
1 Tube & stopper
1 Balloon
Everything dry and clean!!

5. Choose your favorite bottle system to draw – choose either the hot setup or the cold…
Label all the parts to your system – bottle, hot water, cold water, balloon/tube apparatus/cap/bubble, etc.
Identify where in your system there would be low pressure
Identify where in your system there would be high pressure
What happens with this set up that helps you understand where the high pressure and low pressure areas are?

6. In your groups, discuss and answer the following questions…Write your answers in you SNB
Is this a closed or open system?
How did the mass of air particles change?
How did the volume of the air change?
Did you add a push/pull force to the system?
How did the pressure inside the balloon change?
What must have changed about the aps in order to cause the pressure in the bottle to change?

7. Kinetic Energy Model ♬ ♪ ♩
Kinetic energy is energy of motion.
 speed of particles,  amount of KE
 speed of particles, amount of KE
**Gas particles are always hitting other particles and the sides of their container
**This increases the pressure inside the container
After the class discussion, the key ideas are summarized.

8. Kinetic Energy Model ♬ ♪ ♩
 speed of particles,  amount of KE Pressure speed of particles,amount of KE Pressure
Increasing the speed and KE of particles causes them to collide with each other and the sides of the container more often and with more force!!
Therefore, the pressure inside the balloon bottle system increases!!
The opposite happens when speed goes down.
After the class discussion, the key ideas are summarized.

9. Kinetic Energy Model ♬ ♪ ♩
+ Heat NRG =  speed of particles,  amount of KE Pressure −Heat NRG = speed of particles,amount of KE Pressure
The way we increased the speed of the aps was by adding heat energy from the hot water.
The way we decreased the speed of the aps was by cooling the air down or removing heat NRG from aps
After the class discussion, the key ideas are summarized.

10. Expansion and Contraction
Expand/Expansion**: process of increasing volume when heat is added
Contract/Contraction**: process of decreasing voume when heat is removed
**(should be thinking of pressure difference inside/outside that cause this)
Introduce expansion and contraction.
When a volume of gas gets hot, its volume increases. The process of increasing volume is expansion.
Air, like all gases, expands when it gets hot.
When a volume of gas gets cold, its volume decreases. The process of decreasing volume is called contraction.
Air, like all gases, contracts when it gets cold.
When you put a balloon over the mouth of a bottle, you trapped a volume of air inside the bottle and balloon system.
When you put it into the hot water bath, the air inside the system heated up and expanded.
The volume of the trapped air was greater when it was warm than when it was cold. The increased volume filled the bottle and the balloon.
When you put the bottle in the warm water and then put the cap on tightly, you trapped a volume of warm air in the bottle.
When the bottle was put into the cold water, the air in the bottle contracted, taking up a smaller space in the bottle.
The sides of the bottle pushed in when the air inside contracted.

11. Making Sense of Your Observations
What caused the balloon to inflate?
What caused the balloon to deflate?
What caused the tube to blow bubbles when it was in the soap or underwater?
What caused water to go up the tube when it was in the soap or underwater?
What caused the plastic bottle to crush when it was placed in cold water?
Students would discuss the answers to these questions in their groups.

12. Compression/Contraction
A volume of gas that becomes smaller because of pressure is compressed gas. When a gas becomes smaller in volume because of reduced kinetic energy, we say it contracts.
“When we worked with syringes and foam cubes, we were able to push air into a smaller space by applying force to the air. That added force pushed the gas particles closer together, making the volume smaller.”
A volume of gas that becomes smaller because of pressure is compressed gas.
In our last activity we made a volume of gas smaller, too. But we didn’t put pressure on it. Instead we transferred energy away from the gas particles. The lower kinetic energy meant that the particles didn’t hit each other as often or as hard and were able to move closer together.
When a gas becomes smaller in volume because of reduced kinetic energy, we say it contracts.
Show how you can decrease & increase volume of air in syringe.
Can I change the volume of the liquid in this syringe by doing the same things?
Show that you cannot change the volume of the water in a syringe.
Pass around (have several to pass).