水的三态变化 英文版

Changes in three states of water

【Teaching objectives】

Scientific concept：

1、There are various forms of water in nature——Clouds, fog, rain, dew, frost, snow, ice, water vapor……That means water in nature in both liquid, solid and gaseous presence。

2、Water in the natural world constantly undergoing changes in the cycle of three states，The three-state changes to promote water because of temperature changes.

Process and Methods：

1、Recall or observe the various forms of water in nature - clouds, fog, rain, dew, frost, snow, ice, water vapor ... ... discussions between them, changing causes and conditions.

2, seeking the water varies between gaseous and solid evidence, try to design their own water, gas and solid-state changes observed between the experiments.

3, analysis of water between the various states of change in the process of finishing general

three-state variation of the water.

4, think about the nature of water-related issues, and try to use "the water tri-cycle" to explain this phenomenon.

Emotions, attitudes, values：

1, recognizing the observational data (evidence) on the meaning and value of scientific research. 2, preliminary identification of material is constantly changing.

3, the initial establishment of the material eternal point of view.

【Teaching points】aware of water in various states of nature can be changed with each other.

【Education】difficult on the water between the three-state transformation of an explanation.

【Teaching Preparation】

Group: Water morphological changes of the process and changes have occurred in the discussion record form;

Class: a plastic cup, a cup of ice, salt; clouds, fog, rain, dew, frost, snow, ice and other natural phenomena of the picture or image data.

【Teaching process】

First, the introduction of the subject

1, the conversation into: play video small water people (design intent: shock of fun, and lead to student motivation for learning)

2, after reading the students think: There are several small water change of state people? (Gaseous, liquid and solid)

3, located the suspect: water among these three states can change into each other do? Today, teachers and students together to explore the water on a three-state changes (courseware to expose problems, and writing on the blackboard)

Second, new lesson Teaching

(A) recalled the existence of water in the form of nature and discuss the morphological changes of the water course and changed the conditions of

1, courseware were various forms of water to produce pictures of the students according to morphological changes of the water of life experience, he said the name, status, and produced what season or time of day to see such issues as the initial knowledge and understanding of various forms of water . (Design intent: It is to break the focus of this lesson for students to solve a variety of morphological changes of water occurred in terms of the process and pave the way)

2, courseware production of a "morphological changes of the water course and changed conditions" for the students individually think 2 minutes.

(Design intent: to provide students with room for thinking, know what problems can be themselves and what can not. To enable the Panel cooperation is not a mere formality, to reduce the blindness of the discussion.)

3, distribution of forms, learn warm Tip: four-member team note that division of labor, we can discuss together to accomplish the task form (2 - 3 form of water), by the head of a representative of the record, heard the music sound to stop the discussion . A comparison and which team best able to first to complete this challenge.

(Design intent: Each panel discussion on the completion of 2 - 3 on the water conditions, analysis of morphological changes and changes in the purpose is to reduce the degree of difficulty, both within the group reflects the cooperation and reflects the group and group co-operation.)

4, students discuss their process of change and the outbreak of the conditions and to fill out the form issued by the teacher.

5, the exchange of teachers and students together. The completion of courseware in the table (the default may be frost and snow are not necessarily to answer the students draw and produce well in advance of the cream cup presented to us, if the students that came out on the strong praise) (B), the tri-state cycle of water

1, we performed very well, here we are, under a sound easy to see animated segment, "Why would rain"

2, After reading the answer the following questions (courseware to produce). Side of the answer, while the three-state summary of the water change maps. Small water droplets and the earth will be a friend to meet? (Would be so, on the form of rain or snow, hail, etc., a hyperlink to the table slides into the slide.) Together with the completion of the tri-state water cycle diagram. (Design intent: water, three-state variation is the difficulty of this lesson, students independently completed a certain degree of difficulty, so a summary of teachers and students a common understanding of their three-state cycle of water preliminary knowledge and understanding.)

2 students to think: What caused the water of the tri-state change? (Heat or the temperature of the water caused by the change of tri-state changes)

3 students to think and to be able to explain why the total does not overflow the oceans, rivers,