Hot and Cold Water Lesson 2

Hot and Cold WaterLesson 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?

New Vocabulary Assessing our Prior Knowledge • What happens to water when it gets hot? • What happens to water when it gets cold? Here is a dispensing bottle filled with green room-temperature 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 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). 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. Mark the height of the water in the straw with a permanent marker.

Focus Question(What is the problem?) 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. 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 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 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 Water Molecule H H O Cold Water Room Temperature Water Warm Water More Dense Less 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 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

Hot and Cold Water Lesson 2