Land and Water
Lesson 2
The Water Cycle: Modeling Land and Water
In Lesson 2 students will discuss what a model is and how scientists use models. Students will then make a model of land and water and have evaporation, condensation and precipitation form inside their model.
3. Lesson set up and Management
INQB: Scientists plan and conduct different kinds of investigations, depending on the questions they are trying to answer.
INQF: A scientific model is a simplified representation of an object, event, system, or process created to understand some aspect of the natural world.
ES2A: Earth materials include solid rocks and soil, water, and gases of the atmosphere. Materials have different physical and chemical properties, which make them useful in different ways.
- Student will understand what a model is and its role.
- Student will build a model.
- Students will use a model of land and water to observe evaporation, condensation and precipitation.
3. Lesson set up and Management
Materials:
- Have students collect various models during this unit. Display them on a bulletin board. Some items may need to be attached by a string.
- Humus and compost and can be used interchangeably because both are referring to the organic components of soil.
- Teach students how to put the rubber stopper into the clear plastic box from the inside of the plastic box. Number the stopper to match the number on the clear plastic box.
- Pass out the plastic wrap to each group as they are building their land/water model.
- The warmer the water, the better. Caution: don’t make the water hot enough to burn the students.
- Teach students how to clean up. Have one group model for the rest of the class. Have the groups evaluate the speed and neatness of the clean-up. Having paper towels available to dry hands is a big issue. During this science kit you may want to add a class job, paper towel handler if you don’t have a paper towel dispenser near the clean-up/rinse station.
- Rinse buckets need to be placed on top of a flat garbage bag.
- Do not have the students shake the large or small pad. The cotton can fly off, the plastic may come loose and the pad may disintegrate. Have the students brush earth materials off the pads into the garbage can. Over the course of the unit, pads may need to be replaced.
- Damp absorbent pads can be hung over a clothes hanger for drying. The clothes hangers with the pads can then be hung around the room.
Student Management:
- Have the students list and/or bring different types of models. Models represent objects, events, systems, and processes.
- Have the students draw a labeled diagram of the land/water model. Have them label the parts "earth," "water," "plastic wrap," etc. Also have the students label the different parts of the water cycle. Have them underline or highlight in a different color "evaporation," "condensation," and "precipitation."
- Make sure that the students do not bump the desk or table that the clear land/water model is sitting on while waiting for the condensation to form.
- Preconception: Students may not understand where the water droplets on the plastic wrap came from. The water vapor in the air inside the clear plastic box is where the water droplets come from.
- Preconception: Students believe that as soon as water changes from a gas to a liquid [condensation] (water vapor to water droplets) there is precipitation. This model shows the students condensed water vapor that may not have turned into precipitation because the water droplets haven't grouped together to weigh enough to be pulled to the ground by the force of gravity.
Reading Support:
- Using the selection "Tapping into the Water Cycle," have students write summaries for the section "Chile Today-Foggy All the Time!" (see student response sheet and rubric).
- Read selection "Tapping into the Water Cycle." Have the students identify which part of the water cycle is the solution to the problem in the sections; "Collecting Rainfall for Year-Round Use" (precipitation), "Melting Rivers of Ice" (surface water), "Chile Today" (condensation).
- Independent reading opportunity: Rookie Read-About Science: Where to Puddles Go? by Fay Robinson. It does a great job explaining condensation and the other stages of the water cycle with a low reading level (3.2).
- Read-aloud reading opportunity: A True Book: Water by Christin Ditchfield. Part of this book could be used as a read-aloud with Lesson 2. On pages 28-33, it tells about the water cycle and the importance of the water changing temperature during this process.
Math Support:
- Have the student teams measure the amount of earth materials they put into the clear plastic box in order to practice using the volumetric tool, a graduated cylinder. Also, student teams will get a visualization of different volumes.
- Have the student teams figure out "elapsed time" using a click when they need to wait 5 minutes for the water vapor to condense into liquid water.
- Create math scenarios with the activity such as:
- Using the amount of earth materials needed for this activity, what is the percentage or fractional part?
- 1,500 ml sand + 500 ml humus + 500 ml gravel + 250 ml clay = 2750 ml earth materials
- 2750 divide by 250=11 6/11 sand 2/11 humus 2/11 gravel 1/11 clay
- 55% sand 18% humus 18% gravel 9% clay
- Look at the pie chart in the selection "Tapping into the Water Cycle" can you represent this information in another form? (Example: number line)
- Using the amount of earth materials needed for this activity, what is the percentage or fractional part?
- Labeling the diagram of the land/water model supports labeling problem solving in math.
- If the students do the Daily Water Usage chart, there are many different math applications. For example: finding the class average, making a scatter plot of the class totals, finding the class range, comparing the range on a category, finding the class average on a specific category, etc.
Last updated 7/08/2009