Science: Evaporation of water in the Caribbean

Days 1-2

Goals:

1. Recognize the movement of water from land, sea, and air. This is otherwise known as the water cycle.

2. Relate the movement of water to our every day life by showing how it affects climates, ecosystems, plants and animals, and humans.

Time:

180 minutes on first day, 30 minutes second day.

Resources\Materials:

Several glass jars, tape (preferably duct tape), sand, rocks, water, labels, ice cubes, refrigerator, small cups, popsicle sticks, ice cream, bowls, heat source (heat lamp or a window that receives a lot of sun), warm up activity, and an observation sheet.

possible web sites:



http://faldo.atmos.uiuc.edu/bkup/water.cycle.intro.html




http://aggie-horticulture.tamu.edu/kinder/!ole.html

Procedure:

1. Discuss with students the importance of water and explain that our supply of water is finite. It is in one of three forms: gas, liquid, or solid.

2. Explain each state that water can pass through by performing demonstrations of each.



A. For changing a solid (ice) into a liquid, leave the ice cubes out in a dish at room temperature and allow the students to see the change. It is also possible to do this demonstration with ice cream because it is much more fun.

B. For changing a liquid into a solid, give each student a small cup with water in it. Place these cups in a freezer and let them sit for a short while. They will change from a liquid to a solid. It is possible to use cool-aid for this activity and allow the students to make popsicles.

C. For changing a liquid to a gas, boil water using a heat source for 15 - 20 minutes. Prior to boiling, measure the amount of water in the pan. After heating, measure the water in the pan. Allow the students to speculate where the water goes. They all should be able to accurately explain where the water goes. Explain the concept of evaporation which is the change of water from liquid to gas state.



3. Upon completion of the previous activities, introduce the topic of the water cycle.

4. Build a concept web-map of the water cycle so the students knowledge of the subject can be determined.

5. After gauging the students knowledge on the water cycle, perform a warm up activity that allows students to use their prior knowledge on the movement of water. As a class and with the assistance of the teacher, the students will draw a model of the water cycle on the chalk board.

6. Upon completion of the warm up activity, the teacher should discuss the water cycle using a brief review of what was just discussed so the students understand the movement of water in the water cycle..

7. Now, students will perform a culminating activity that will require them to build a device that will show evaporation and condensation of water.



A. Arrange students into groups of two.

B. Each group will collect materials needed for the following task: glass jars (2), labels, sand, rock, water, and a piece of duct tape.

C. In one jar, students will pour 1/2 inch of sand, 1/4 inch of water, and one stone in the jar. This represents an ecosystem that is a closed system, just like the planet Earth.

D. Next, students will place the other glass jar on top of the one with sand in it and tape both open ends together.

E. Students will now place this device in a window that receives a lot of sunlight or near a heat source. What should happen is the water, once heated, will evaporate in the container over a period of time. At the end of the day, the students should note the level of the water in their jar.

F. For 30 minutes the next day, preferable in the afternoon, place all the jars in the refrigerator. The heated water will condense to the sides of the jars. Before placing the jars in the refrigerator, note the amount of water in the container. Is it less than the 1/4 inch we placed in the jar? Two states are present here: liquid water through condensation, and gaseous water which is present in evaporation.



8. For the remainder of the class session, discuss implications of what would happen to plants, animals, and humans if the water in them froze or evaporated.



A. What would they do to fix this situation or what would happen to their bodies.

B. Relate this to the Caribbean as well as the climate the students live in.

C. For the Caribbean, people wear less clothing than people in colder climates. They lose a lot of water to evaporation. Ask students what the people in the Caribbean must do to prevent water loss. Discuss what plants do to prevent water loss (they have waxy coats that prevent water loss).

D. For the colder climates (like Wisconsin), people wear clothing to prevent water from freezing, not evaporating. Discuss the differences with students.

E. How do plants, animals, and humans adapt to cold and hot areas? How do they prevent evaporation and freezing?



9. Bring the whole activity together by performing one last experiment as a group. Use a heat source to boil water. Once the water is boiling, place several ice cubes in a frying pan and then place this over the boiling water. Students will see the water evaporating, but when the water comes into contact with the cold bottom of the pan, the gas will condense on the bottom of the pan and fall back into the boiling water. This is a good way to summarize the whole activity.

Assignment:

Each student will write a short one page paper on how he/she thinks what was covered in today's class affects the weather in the Caribbean and the climate they live in. The paper must include the following:
A. A title.

B. How the concepts discussed in class affect the Caribbean.

C. How the concepts discussed in class affect the region we live.

D. What we liked and disliked about this class activity.

E. Complete and clear sentences using proper grammar. Students will be assessed by using the rubric that follows. This paper must be handed in on the following day.

Assessment:

Students will be given credit for performing all the tasks required of them. Those tasks include building a evaporation device, building concept maps, and performing a warm up activity.

Rubrics:

Task completion:


4 The student actively performs and completes required tasks presented to him/her.

3 The student performs and completes required tasks presented to him/her.

2 The student passively performs and completes required tasks presented to him/her.

1 The student passively performs, but does not complete required tasks presented to him/her.



Sentence structure:



4 The student writes in complete and accurate sentences and makes no grammatical errors.

3 The student writes in complete sentences and makes few grammatical errors.

2 The students writes in complete sentences, but makes many grammatical errors.

1 The student writes in fragments and makes grammatical errors.



Paper requirements:



4 The student addresses all components expected of him/her in a clear and organized manner and in addition, enhances their paper by using illustrations or diagrams.

3 The student addresses all components expected of him/her in a clear and organized manner.

2 The student addresses all components expected of him/her, but not in a completely clear and organized manner.

1 The student addresses most components expected, or fails to organize the paper, in a clear and orderly manner.

Curricular Strands:

Language Arts - completing warm up activity

Science - phases of water, water cycle, plants, animals, and humans

Math - measurements

Art - building evaporation device

Cooperative learning - working with others

Possible Extensions:

Cook a food like macaroni and cheese to demonstrate the principles of evaporation. Make ice cream to show freezing of water. Go to a sauna (please use care here, you are liable for your children. Expose them to just a few seconds in a sauna.) to demonstrate the effects of evaporation of water and what it is like in a hot climate like the Caribbean. Challenge the students to find the fastest way to dry a towel that is soaked with water and then implement that idea.

This page submitted by St. Norbert College Ocean Voyagers Program