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S3ETS: Supporting Science Success for Elementary Teachers and Students

Session 2

Today’s Agenda: February 17, 2015

Element / Details
Content Focus / Standard 1: Students will understand that water changes state as it moves through the water cycle.
Objective 2: Describe the water cycle
Content Objectives / Teachers will describe the molecular motion of water in the three states or phases and when it is undergoing a phase change.
Teacher will construct both physical and representational models of condensation, precipitation and evaporation.
Teachers will compare heat sources used in class and the sun’s role in the water cycle.
Teachers will construct a model or diagram of the water cycle and brainstorm ways to introduce these types of models to their students.
Language Objectives / Teachers will correctly use higher level vocabulary when communicating about water phases and cycles.
Teachers will use sentence stems or sentence frames provided to write about processes in the water cycle.
Lesson Sequence
ILO Alignment / 1. Inquiry: Would you like your tea hot or cold?
2. S3ETS Business- Dina Dritz
3. Reading Guide and Informational Text
Bonus: Dew point and boiling point
4. Modeling evaporation, condensation, and precipitation for conceptual understanding
a) Physical Models
b) Visual Models
c) Written Description of Process
d) Limitations of Models
e) Water Cycle Diagram
5. Homework – take a lesson you’ve done before and make it more student-centered.

Case Studies: Phase Changes of Matter

A1-After washing your jeans, you decide to hang them up on a clothesline to dry. Explain HOW they will dry using phase changes of water.
Possible student explanation:
The water molecules start in the liquid state/phase. They can move freely and touch each other. When the jeans are hung outside, the water molecules absorb thermal/heat energy from the sun. As each water molecule gains more energy, it escapes and goes flying off the jeans into the surrounding air. Now the molecules are in the air in the gas phase/state. This process is called evaporation. /
liquid + energy gas / Since the jeans are wet, they contain water in the liquid phase. The water molecules are touching, but not tightly packed. They are able to move around and soak the jeans. When you hang them outside, the water molecules gain energy from the sun. This thermal energy is absorbed by the water molecules so that they can change phase. When each molecule has absorbed enough energy to move apart from other molecules, it will change into the gas phase. In the gas phase, molecules move with high energy and leave the jeans. They go flying off the jeans into the air.This is how the jeans dry. This process is called evaporation.
A2-You have been swimming all afternoon. You get out of the pool and dry off with your towel. Explain HOW your towel will eventually dry using phase changes of water.
Possible student explanation:
The water molecules start in the liquid state/phaseon the towel. They can move freely and touch each other. When the wet towel is left outside, the water molecules absorb thermal/heat energy from the sun. As each water molecule gains more energy, it escapes and goes flying off the towel into the surrounding air. Now the molecules are in the air in the gas phase/stateas the towel dries off. This process is called evaporation. /
liquid + energy gas
/ When you dried off with the towel, you added water to the towel. Now the towel is wet with water in the liquid phase. The water molecules are touching, but not tightly packed. They are able to move around and soak the towel. When you leave the towel in the sun, the water molecules gain energy. This thermal energy, absorbed by the water molecules, helps them change phase. When each molecule has absorbed enough energy to move apart from other molecules, it will change into the gas phase. In the gas phase, molecules move with high energy and leave the towel. They go flying off into the air. This is how the towel dries. This process is called evaporation.
B1-On a hot, summer day you take a cold soda can out of the fridge. You set it on the counter and make yourself a sandwich to go with it. When you pick up your cold soda, the outside of the can is wet. Explain HOW the outside of the can got wet using phase changes or water.
Possible student explanation:
The water molecules start in the gas state/phasein the air as water vapor. When the water vapormolecules hit the cold can,their energy is transferred to the can. As each water molecule losses energy, it changes from a gas to a liquid, or condenses, and collects on the outside of the can. This processes is called condensation. /
gas - energy liquid
/ When you take a soda can out of the fridge, the can and the liquid inside the soda can are cold. The air surrounding the can is warmer and contains water vapor. This water vapor is in the gas phase, moving quickly and is invisible. When the water vapor molecules randomly hit the soda can, the heat in the gas molecules is absorbed into the can. Since the vapor molecules loose energy, they slow down and change into a liquid. As more and more water vapor molecules hit the outside of the can, they also loose energy and change phase. Over time, they form drops of water on the can until the can is wet on the outside. This process is called condensation.
B2-After a hot, steamy shower your bathroom mirror is fogged over. Explain HOW your mirror got fogged over using phase changes of water.
Possible student explanation:
The water molecules start in the gas state/phasein the air as water vapor from the steamy shower. When the water vapor molecules hit the cold mirror, their energy is transferred to the mirror. As each water molecule losses energy, it changes from a gas to a liquid, or condenses, on the surface of the mirror.The water collects on the mirror and the mirror gets wet. This processes is called condensation. /
gas - energy liquid

/ When you take a steamy shower, water vapor fills the air. This water vapor is in the gas phase, moving quickly and is invisible. When the water vapor molecules randomly hit the cold mirror, the heat in the gas molecules is absorbed into the cold mirror. Since the vapor molecules loose energy, they slow down and change into a liquid. As more and more water vapor molecules hit the cold mirror, they also loose energy, change phase and condense. Over time, they form drops of water on the mirror until the mirror is covered in water droplets. This process is called condensation.
C1-During the winter, you notice that there is a layer of ice on your favorite fishing pond. Explain HOW the ice formed on the pond using phase changes of water. /
liquid - energy solid
/ Freezing: Similar to condensation
C2-You want some ice for your drink. When you open the freezer, you notice that you are out of ice! Then you notice an empty ice tray. You fill it with water. Explain HOW ice is made using phase changes of water. /
liquid - energy solid
/ Freezing: Similar to condensation
D1-One snowy winter day, you go outside and build a snowman. The next day, the sun comes out and your snowman disappears. Explain HOW your snowman disappeared using the phases of water. /
solid + energy liquid
/ Thawing: Similar to evaporation
D2-You are eating a bowl of delicious ice cream. Your phone rings and you take the call, talking for 20 minutes. When you pick up your bowl, there is liquid goop in your bowl. Explain HOW your ice cream changed into liquid goop using the phases of matter. /
solid + energy liquid

/ Thawing: Similar to evaporation

Sentence Frame Ideas for Changes in States of Matter

1. The molecules start in the ______state.

2. The molecules are ______in the ______state.

3. When you ______energy to a ______, then the

molecules move ______.

4. When ______the energy in the molecules ______.

5. When molecules ______energy, the molecules move ______

and change from a ______to a ______.

6. When a ______changes to a ______this is called

______.

Answer to Science Question # ______

Name ______

Rewrite the Question:
What is still unclear to you?
What new questions do you have about our topic?

How Do Your Jeans Dry?

When you wash your clothes they become wet. You can’t wear them that way, so they have to dry. Most of us would throw those clothes in a dryer and turn it on. But what if you had no dryer? Most people of the past, and many people today dry their clothes by hanging them in the sun. How does this help? Let’s find out.

1. Use the blue construction paper to cut out two pairs of pants. They should be the same size: about 4 inches long and about 1 inch wide.

2. Set up two clotheslines. Place a dowel in each wooden holder. Add some washers to make it stable. Place the two poles about 10 inches apart.

Tie a string between them to make the clothesline.

It should look like this:

Be sure to make two of these.

The first one will be for drying our jeans in the sun, the other will be our control. We’ll use it to dry jeans without the help of the sun.

3. Now use the pipette to drop 10 drops of water on each pair of jeans. Let the water soak in. Attach one pair of jeans to each clothesline using paperclips or clothespins.

4. Set one clothesline in a shaded part of the classroom or outside. Set the other clothesline under a lamp or in direct sun.

5. Use a graph and a timer to keep track of how long it takes for the jeans to dry. Here is a sample graph for you.

Jeans Drying

Percent dry / 100
80
60
40
20
0
0 5 10 15 20
Time in Minutes

Did you figure out how the jeans dried? What word would you use for that?

Cold Soda, Warm Soda

It’s a hot day. You want a cold soda. You take one out of the refrigerator and set it down on the table while you go find a glass. What happens to the soda can when you leave it for a little while? Let’s find out.

1. Take two paper towels and place them on the table about a foot apart.

2. Place a room temperature soda can on one of the paper towels. This is our “control.” A control is something that we can use to determine if changes are taking place in our experiment.

3. Take a cold can of soda out of the refrigerator. Wipe it with another paper towel to ensure it is dry on the outside. Place it on the table on top of your second paper towel.

4. After 2 minutes check the outside of each can. Write and draw what you see. Be sure to label each can.

5. Check the cans again every 2 minutes for 10 minutes. What happens? Why do you think it is happening?

6. Discuss with your group how this relates to the water cycle. What is the process you witnessed called?

Cooling off the Kettle

The steam rising from a boiling kettle is not water vapor. Instead, invisible water vapor rises above the kettle, cools, and condenses into what we call steam. It’s really a kind of cloud! Once it rises farther into the atmosphere, the molecules are able to move away from each other and become invisible again. This happens in the sky as well. Clouds will form, then disappear when the water droplets gain enough energy to become vapor. But some other things can happen. Let’s look at that.

1. Fill the tea kettle half full of water. Put it on the hotplate and turn it on high.

2. When the water begins to boil, put several ice cubes in the metal pie pan.

3. Now pick up the pie pan with the tongs. Hold it about 1 foot above the tea kettle so the steam and water vapor can touch the cold underside of the pie pan.

4. Watch what happens. Write and draw your results. Think of reasons this may happen. How is this like what happens in clouds?

Something to discuss: What are those bubbles that form on the bottom of the tea kettle?

Would You Drink That???

In Utah, nearly all of our drinking water is treated before we drink it. The water treatment plant tests the water for purity and uses chemicals, and other methods of treatment to be sure the water is safe to drink. However, materials called “dissolved solids” are left in the water. Let’s see if we can find some of them.

1. Fill the beaker with 20 ml of water.

2. Set up the alcohol burner and stand. It should look like this:

3. Place the beaker on top of the stand.

4. Remove the protective lid and light the burner.

5. Allow the water to heat up and boil. Leave it there until it

boils completely away.

6. Extinguish the flame on the burner and let the beaker cool off for

at least 5 minutes.

7. Check the inside of the beaker. What do you notice? How did this stuff get there? What do you think it is? What would happen if you refilled the beaker and did the experiment again without first cleaning out the beaker?

Something to think about: How is the beaker like the Great Salt Lake?

Global Water Fluxes and Reservoirs

Source:

Source:

C Penrod SLCSD 2015