TESLA Water 2011

IceLesson 3

The Big Idea of this Investigation

Water, which covers most of Earth's surface is the only substance on Earth that is found naturally in all three states of matter. Water can change from one state to another depending on the amount of heat that is added or taken away from it.

ENGAGING SCENARIOENGAGING SCENARIO

The Aquatic Center really liked your information about the properties of hot water and cold water. Now they would like for you to try out some activities for another part of the field trip events they are planning. They are trying to figure out what happens to water when it gets really cold. Again, they have sent us some materials and printed information that may help us figure this out. They also need us to keep accurate records and labeled drawings in our science notebooks so we can send them a report when we finish the activities. What we learn about water will help them decide whether to use the activity with students who visit.

• What is the problem we need to solve? • What do we need to investigate?

Kit InventoryKit Inventory

• What color/shape is the object?• Where have you seen this object before?• What do you think we will use this for in the unit?

• What color/shape is the object?• Where have you seen this object before?• What do you think we will use this for in the unit?

These are the objects that have been sent to us by the Aquatic Center. I have put them in this large bag. Let’s see if we can identify them.

These are the objects that have been sent to us by the Aquatic Center. I have put them in this large bag. Let’s see if we can identify them.

Focus Question (What is the problem?)Focus Question (What is the problem?)

What happens to water when it gets really cold?What happens to water when it gets really cold?

NOTEBOOK ENTRY

Discuss with your group of scientists a possible focus question for this investigation.

Prediction (related to the focus question) Prediction (related to the focus question)

I think that when water gets really cold it will __________ because…I think that when water gets really cold it will __________ because…

NOTEBOOK ENTRY

Our Plan

1. Submerge a vial in a 1-liter container of water to fill it to the top.2. Lift the vial out of the water carefully and place it on a paper towel.3. Push the cap on, making sure not to spill any of the water.

1. Start with the plunger of the syringe all the way down.2. Place the tip of the syringe in a cup of water and draw up 50-ml.3. Point the tip of the syringe upward and push out any air in the syringe.4. Point the tip back into the water and push the plunger until the syringe

hold exactly 40-ml of water when the bottom of the rubber tip on the plunger is right at the 40-ml mark on the syringe barrel.

5. No squirting your teammates!

Filling the Vial with Water

Filling the Syringe with Water

Collecting DataCollecting Data

Scientists always try to make careful observations.

Vial Syringe

Before Freezing

NOTEBOOK ENTRY

Vial Syringe

After Freezing

Making Meaning ConferenceMaking Meaning Conference

Why did the water do this? Our earlier investigations said that water condenses or contracts when heat is removed.

What happened to the water in the vials and syringes when we placed them in the freezer?

What happened to the water? Why is it above the rim of the vial and filling more space in the syringe?

Dance of the Molecules: What happens to the water molecules when they become a solid?

Claims and Evidence

Use your own words, or words from the word wall, to help you complete the following sentences in your science notebook.

I claim that when water freezes it ____________________

I know this because…

I claim that when water freezes it ____________________

I know this because…

NOTEBOOK ENTRY

Density of IceWe now have evidence that water expands when it freezes, but the Aquatic Center would also like you to look at another unique property of ice…..density.

We now have evidence that water expands when it freezes, but the Aquatic Center would also like you to look at another unique property of ice…..density.

I think that ice is…because…I think that ice is…because…

NOTEBOOK ENTRY

Which is more dense, water or ice?

Prediction Prediction

Don’t forget about your previous experiences with water and density.

Our Plan

1. Prepare one cup with 100ml of water frozen into ice.2. Fill a second cup with water to the same level as the cup of ice.3. Confirm that both containers have the same volumes of water.4. Place both containers on a balance to see if they weigh the same.

--Does one cup of ice have the same density as one cup of water?

1. Prepare ice cubes colored with blue food coloring.2. Carefully place the ice cubes in a cup of water and observe what

happens.

-- What do you think will happen if we put the blue ice cubes in a cup of room temperature water.

Comparing 100ml of Water with Ice

Blue Ice Cubes

Collecting DataCollecting Data

Scientists always try to make careful observations.

Water and Ice on a Balance

NOTEBOOK ENTRY

Blue Ice Cubes in Water

Making MeaningWhich weighs more, an equal volume of ice or water?

What happens to the volume of ice when it melts? Does water take up as much space as ice?

Why was the cup of water heavier than the cup of ice?

What happens when the ice is placed in water?

Why did the blue colored water go to the bottom of the cup?

Density of Water

OH H

Water Molecule

Cold Water Ice

Less DenseMore Dense

When water is cooled the molecules become less active and take up less space. Notice the number of molecules in the box.

When water becomes really cold it does something unique, it turns to ice. To become a solid, the molecules form a hexagonal bond and they take up more space. This causes ice to be less dense then both cold or warm water.

Claims and Evidence

Use your own words, or words from the word wall, to help you complete the following sentences in your science notebook.Preparing the Investigation

I claim that ice is less dense than…

I know this because …

I claim that ice is less dense than…

I know this because …

NOTEBOOK ENTRY

Reflection/ConclusionReflection/Conclusion

Revisit your original prediction and respond to one of the following stems:

My prediction was accurate or was not accurate because…..

I wish to revise my prediction because…

My original thinking has changed because…

What did you learn…?

What really surprised you…?

What new questions do you have…?

What would you like to know more about…?

NOTEBOOK ENTRY