楊艷

一、熱身活動(dòng)

師： This unit we will talk about the topic science. Do you interested in science？

生：Yes.

師：What kinds of experiments have you done in science class？

生：會(huì)吸紙的梳子、魔術(shù)乒乓球 ……

師：Yes， many interesting experiments.

二、導(dǎo)入課題

師： Students， look at what I bring here today. A jar， a piece of cardboard and some water. Guess what we are going to do today.

生： We are going to do an experiment.

師： Yes we are going to do an interesting experiment. are you interested in it？

生： Yes.

師： Now lets do an experiment.

三、展示新知

師： In this lesson， there are a few new words. At first ， lets divide the syllables of the words.

I ll give you several minutes to spell the words. We will see who can pronounce the words correctly.

生1： correct， method， force，jar， experiment

生2： experiment重音讀錯(cuò)了，應(yīng)該是第二個(gè)音節(jié)重讀.

生3： method 的th 讀錯(cuò)了。

師： You are right. Now follow me please. Next I ‘ll do the experiment. Please look at me carefully.

I fill a jar with water. I cover the top with a piece of cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. Can you guess what will happen？

生1： The water will pour out.

生2： And the floor will get wet.

生3： I dont agree. I think the water will stay in the bottle.

師： 現(xiàn)在見證奇跡的時(shí)刻到了。lets see what will happen. Oh， the water wont pour out. It stays in the jar.

四、鞏固練習(xí)

師： Please listen to the tape. Its about how to do the experiment. Please fill in the blanks while listening to the tape.

1. ____ a jar _____ water.

2. ____ the jar _____ a piece of cardboard.

3. ____ the jar upside _____.

4. ____ your hand _____ the cardboard.

生1： F ill a jar with water.

生2： Cover the jar with a piece of cardboard.

生3： Turn the jar upside down.

生4： Take your hand off the cardboard.

師： Great， you are right. Now please open your books. Read the lesson silently. You should finish the exercise after reading. Here is the exercise.

Read the text. Put the sentences in the correct order.

（ ） Put a piece of cardboard over the jar.

（ ） The jar of water is upside down， but the water stays in the jar. This is because air pressure pushes the cardboard onto the jar.

（ ） Fill the jar with water.

（ ） Turn the glass jar over quickly. Hold your hand on the cardboard for a few seconds.

（ ） Remove your hand from underneath the jar. What happens？

（ ） There is more air outside the jar than inside， so there is more air pressure outside than inside.

生： The order is 2，5，1，3，4，6

師： Well done， everyone. you have already understood this experiment.

五、合作探究

師： Now please work in groups and try to do the experiment again. During the experiment， we should try like this：

What happens when you use less water？

What happens when you use more water？

What happens when you use wet cardboard？

What happens when you use a bigger jar？

What happens when you use a smaller jar？

Each group should present their report in class.

小組1： I fill a jar with less water. I cover the top with a piece of cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. The water wont pour out.

小組2： I fill a jar with more water. I cover the top with a piece of cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. The water wont pour out.

小組3： I fill a jar with water. I cover the top with a piece of wet cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. The water pours out.

小組4： I fill a jar with water. The jar is smaller. I cover the top with a piece of cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. The water wont pour out.

小組5： I fill a jar with water. The jar is bigger. I cover the top with a piece of cardboard and hold it there. Then I turn the jar upside down and take my hand off the cardboard. The water wont pour out.

師：Well done， everyone！ Science is interesting. If we work hard to look into science， we will find science very amazing.

六、課堂小結(jié)

Today we have learned an experiment. We know the water will stay in the jar. More water or less water， it doesnt matter. Smaller jar or bigger jar， it also doesnt matter. Do you know why？ Because the air pressure helps the cardboard hold the water in the jar.