Hot and Cold Water
Lesson 2
TESLA Water 2011
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 SCENARIO
The Aquatic Center really liked your information about the
properties of water, especially the part about surface
tension. 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 different ways
students can find out what happens to water when it gets
warm and what happens to water when it gets 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 because have been asked to send a report in a
couple of weeks. They want us to share what we learned
about water so they will know whether to use the activity
with students.
• What is the problem we need to solve?
• What do we need to investigate?
Kit Inventory
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.
• 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?
Assessing our Prior Knowledge
•What happens to water when it gets hot?
•What happens to water when it gets cold?
New Vocabulary
Here is a dispensing bottle filled with green roomtemperature water. When ever you see green water in this
lesson you can assume that it is at, or near, the same
temperature as the room.
This is some of the new equipment that the Aquatic Center
has sent us. They want us to work in groups to make a
piece of equipment to investigate what happens to room
temperature water as it warms and cools.
Directions for Assembling the Aquatic Center Materials
1.
2.
3.
4.
5.
Moisten the hole in the stopper and the end of the straw
Insert the straw into the wider end of the stopper
Push the straw as far as it will go with care.
The straw does not need to go all of the way through the stopper.
I will fill your glass bottles with room temperature water (almost to
the top).
6. Push the stopper into the top of the bottle to form a very snug fit.
Water will rise into the straw. You want the the water to rise almost
1/2 the height of the straw.
7.
Mark the height of the water in the straw with a permanent marker.
One of the activities that the Aquatic Center wants to try out
has something to do with water when it gets warm or cold.
The Aquatic Center has sent us the bottle system we
assembled, to see if we can find out what happens to water
when it gets hot or cold.
Focus Question
(What is the problem?)
How can we use the materials we received from the
Aquatic Center to find out what happens to water when
it gets warm or cold?
NOTEBOOK ENTRY
The Aquatic Center has also provided us with one more
piece of information. They suggest that we try placing the
bottle system that we assembled in water that is hot and
that is cold.
Prediction (related to the focus question)
I think that when the bottle system is placed in hot water,
the water in the straw will ______________ because…
I think that when the bottle system is placed in cold water,
the water in the straw will ______________ because…
NOTEBOOK ENTRY
Solving our Problem
When you test your predictions I need you to observe
and describe what you see.
Scientists always try to make careful observations.
Our Bottle System
Room Temperature
Water
Added to Hot Water
Added to Cold Water
NOTEBOOK ENTRY
Making Meaning Conference
What happened to the water level in the straw when bottle system
was added to hot water?
Why did the water level rise, or move up, inside the straw?
What happened to the water level in the straw when the bottle
system was added to cold water?
Why did the water level drop, or move down, inside the straw?
What is another system that pushes liquid up and down a tube
when temperature changes?
New Vocabulary
Expands: As water gets warmer, it takes up more space.
Contracts: As water is cooled, it takes up less space.
Thermometer:
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 is heated it ____________ and
when water is cooled it _______________.
I know this because…
NOTEBOOK ENTRY
Part II: Hot and Cold Water
The Aquatic Center is very pleased with what we have
learned about water when it is heated or cooled. Today
they have a new problem they would like us to solve.
This problem is also part of the activities they have
planned for their field trips. They are trying to figure out
what happens to hot or cold water when it is put into
room temperature water.
• What is the problem we need to solve?
• What do we need to investigate?
Focus Question
(What is the problem?)
How can we use the materials we received from the
Aquatic Center to find out what happens to water when
it gets warm or cold?
NOTEBOOK ENTRY
Many of you have a lot of experiences with placing different
objects in water . Before we begin working to solve our
focus question, I would like you to predict and observe what
happens when I place some objects into a cup of water.
I would like you to make a label drawing of a cup of water
and record what you observe in your science notebook
Objects: Rubber Stopper
Wooden Bead
Cork
Penny
New Vocabulary
Floats ---> Less Density
Sinks ---> Greater Density
The Aquatic Center has sent along some additional materials for
us to use to try to solve their problem. I will demonstrate how we
can assemble the materials for this investigation.
Using the ladle system we will carefully dunk a ladle full of hot or
cold water into a cup of room temperature water.
The Aquatic Center recommends that we color our hot water red
and our cold water blue so we can see what happens when the
water is placed into room temperature water.
Prediction (related to the focus question)
I think that hot water in the vial will ______________ when
placed in room temperature water because…
I think that cold water in the vial will ______________
when placed in room temperature water because…
NOTEBOOK ENTRY
Collecting Data
Hot water placed in
room temperature
water
Cold water placed in
room temperature
water
NOTEBOOK ENTRY
Making Meaning
What happened to the hot water in the vials?
Why do you think this happened? Why did some objects
in the earlier demonstration float in the cup?
What happened to the cold water in the vials?
Why do you think this happened? Why did some objects
in the earlier demonstration sink in the cup?
Density of Water
H
O
H
Water Molecule
Cold Water
More Dense
When water is cooled the
molecules become less
active and take up less
space. Notice the number
of molecules in the box.
Room Temperature Water
Warm Water
Less Dense
When water is heated the
molecules become more
active and take up more
space. Notice the number
of molecules in the box.
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 cold water is _____________ than room
temperature water. I also claim that hot water is ________
than room temperature water.
I know this because …
NOTEBOOK ENTRY
Reflection/Conclusion
Revisit your original prediction… Explain how the evidence
did or did not support your original prediction?
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