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      八下Unit 6全英教案[5篇模版]

      時間:2019-05-15 06:09:16下載本文作者:會員上傳
      簡介:寫寫幫文庫小編為你整理了多篇相關(guān)的《八下Unit 6全英教案》,但愿對你工作學(xué)習(xí)有幫助,當(dāng)然你在寫寫幫文庫還可以找到更多《八下Unit 6全英教案》。

      第一篇:八下Unit 6全英教案

      Unit 6 How long have you been collecting shells?

      Period 1 Section A I.Teaching aims and teaching demands:

      In this unit students learn to talk about how long you have been doing things.II.Teaching key and difficult points:

      A.Vocabulary

      collect, inline, marathon, skate, stamp, shell, globe, monster,particularly, run out of, be interested in,last year, times, numbers, How long…? birthday, penguin, hobby, kite B.Target language How long have you been skating? I’ve been skating since nine o’clock.When did you start skating? I started skating at nine o’clock.Students are skating at the Hilltop School.C.Structures Present perfect progressive Simple past tense Present progressive tense III.Teaching methods: Audio-lingual methods IV.Teaching aids: a tape recorder V.This unit is divided into eight periods.Period2 Section B I.Teaching aims and demands : Students practice using the target language.II.Teaching key and difficult points:

      A.Vocabulary stamp, collect stamps, kites, B.Target language ①What does he collect? He collects kites.②How long have you been collecting these kites? Since I was ten years old.③How many do you have?

      I have about 35.④I collect shells because they are beautiful.⑤I’d like to collect stamps because they are interesting.Step 1 Grammar Focus

      Go through grammar focus with the students together.Step 2 Reading(3a.)Task 1.Read the passage.Task 2.Explain some difficulties by the teacher.① talk to sb.② raise money

      ③ the first one to

      ④ an hour ago ⑤ How long have you been playing Task 3.Find the sentences of the Present Perfect Progressive Tense by students.Step3 Group work

      Finish 3b and 4.Step 4.Pairwork 2b This activity reviews and introduces selected vocabulary.Task 1.Ask a student to read the sample answers and then fill in the chart and tell your partner what you collect and what you would like to collect, say why.Task 2.First read the conversation in the box, then ask students to work in pairs to talk about their answers.Task 3.Have some pairs act their conversations to the class.Step 5.Listening 2a This activity gives students practice writing the target language and understand it in spoken conversation.Task 1.Read the instructions.Say you will hear three conversations.They are about Bob, Marcia , and Liam and their collections.First of all, let’s look at some key words.so far 到目前為止

      stuffed animals 填充玩具動物

      an interesting collection 一個有趣的收藏 theater and movie tickets 電影票

      Task 2.Play the recording the first time.Students only listen.Task 3.Play the recording a second time.Ask the students to fill in the table.Then correct the answers.Step 6.Listening 2b Listen carefully.Then check the answers.Step 7 lead in Look at the four pictures and answer the following questions.1.What can you see in the pictures? 2.What are they? Step 8 Reading(3a)1.Read the passage by students and draw lions connecting each snow globe and its description.2.Explain some difficulties by the teacher.3.Find the sentences of The Present Perfect Progressive Tense.Step9Writing(3b)

      1.First ask students to complete the message according to Activity 2a.2.Check their answers.3.Show a sample message on screen by a projector and ask students to read by themselves.Step 6 Group work(4a)

      Make a survey about everyone’s hobby.Find out how long they have been doing their hobby.Task 3.Teach these words:

      1.因為做某事而感謝某人:thanks /thank sb for doing sth.=give/return thanks to sb for doing sth 2.因為某事而感謝某人:thanks/thank sb for sth=thanks to sb for sth 3.事實上:in fact=as a matter of fact 4.我最喜愛的(人、物):my favorite 5.不得不(客觀因素):have to do sth I had to work for a boss in order to make a living.(為了生存,我不得不為老板工作)

      6.一定、必須(主觀因素):must do sth I must work hard.(我必須努力工作)7.用完:run out of 無意碰到,跑過:run across 追趕:run after 逃跑:run away 自來水:running water 8.使某事由別人做/遭受了……、:have sth/sb+過去分詞

      I'm going to have my shoes mended tomorrow.(明天我去補鞋子)She had her hands burned.(她燒傷了她的手)①使某人做某事:have/let/make sb do sth ②使……處于……、狀態(tài):have sb/sth doing sth ③have a good time/a lesson/a meeting/a rest/a talk/a swim.....④穿著 :have on ⑤和某人講話:have a word with ⑥最好:had better do sth 9.北極熊:polar bears 10.別人:anyone else=anybody else 別的一些事情:something else 別的任何事情:everything else 沒有別的事情:nothing else 別的什么事情:what else 11.在某人……歲生日:on one's +序數(shù)詞 birthday

      on my seventh birthday(在我7歲生日的時候)12.到處:be all around

      13.帶有動物的玻璃器:globes with animals 14.讓(使)某人做某事:let/make/have sb do sth 有這種用法的還有一些感官動詞:

      see sb do sth

      hear sb do sth

      notice sb do sth

      feel sb do sth

      watch sb do sth

      如果接-ing形式,則表示動作正在進行。15.順便說一句:by the way 16.在去……、的路上:on the way(to)....17.擋路:in the way 18.用這種(那種):in this(that)way 19.在某種程度上:in a way 20.決不:in no way 21.迷路:lose one's way 22.喜歡做某事:like to do sth/like doing sth 23.大約兩年:about two years 24.告訴關(guān)于……、:tell about...25.制作一個……的清單:make a list of....26.完成做某事:finish doing sth 27.對……感興趣:be/become interested in....28.每兩年:every two years.29.把某物送給某人:send sth to sb=send sb sth 30.停止做某事:stop doing sth 31.停下來做某事:stop to do sth Step 6.Writing

      Task 1.Read the instructions.Task 2.Ask the students to write the e-mails on their own.Task 3.Ask some students to read their e-mails to the class.Step 7Homework 1.Review the vocabulary.2.Write your own conversations about your collections.Period3 Reading and writing I.Teaching aims and demands : Students practice the target language by reading and writing.II.Teaching key and difficult points: A.Vocabulary

      the capital of,a city with a very colorful history,in Russian style,more than,be welcomed by,Chinese history,be far from,be certain B.Target language

      ① This is an teresting city with a very colorful history.② Since I came to China, I’ve been learning a lot about my family history.③ I think if you study hard, you’ll be able to understand any culture III.Teaching methods: Audio-lingual methods and Control-writing.IV.Teaching aids: a tape recorder V.Teaching procedure Step1 Dictation Step 2 Selfcheck(Part 1)1.Get students to fill in the blanks and then check their answers.2.Make their own sentences with the words.Step 3 Self check(Part 2)1.Get students to read the ad.2.Ask students to finish the letter on the own.3.Check their answers and five some explain.Step 4 Reading: I’ve been studying history in China.Section 1 Before you Read:

      Ask students to answer the following questions: ① How mush so you know about history? ② How many Chinese dynasties can you think of? ③ How many famous characters from Chinese history can you think of?(make a list)④ Can you think of famous characters from the history of other countries Step 5 Section 2 While You Read: Reading strategy

      Let students scan the text quickly to find details that they are looking for.Tell students they can find information quickly without reading the whole text Step 6 Section 3 After You Read:

      Ask students to go through the reading again.Then have them complete the sentences below.1.Leo has been teaching in China for_______.2.Some buildings in Harbin are______.3.The _______ welcomed the first Jewish settlers to China.4.In Australia, students usually study _______ and ______ history.5.The more Leo learns about ________, the more he enjoys ______ in China.Step 7 Group work(3b)1.Divide students into groups of three.2.Show the conversations in 3b on th3e screen.3.Ask students to practice the conversations, then let them make their own conversations according to3b.Step 8 Summary Key words: 1.the capital of …的省會/首都 2.with a very colorful history有著非常豐富的歷史 3.European influence 歐洲化影響 4.be in…style 具有……的風(fēng)格 are in Russian style俄羅斯風(fēng)格

      5.So it was very interesting for me to learn that a lot of Jews came to live in Harbin many years ago.很多年前就有很多猶太人來到哈爾濱居住,這對我來說了解這一歷史是非常有趣的。

      6.In fact, the first Jews probably came to Kaifeng more than a thousand years ago, and were

      welcomed by the Song Emperor.事實上, 最早的猶太人可能一千多年前就來到了開封, 他們受到了宋朝皇帝的熱情歡迎。

      7.It is + 形容詞+for sb to do sth 對于某人而言, 做某事很…… 如: 對你來說完成此工作很容易。It’s easy for you to finish this work.對外國人來說學(xué)中文有點難。

      It’s a bit difficult for foreigners to learn Chinese.8.However, when I heard that I was going to work in China, I started studying Chinese history.然而, 當(dāng)我聽說我將在中國工作的時候,我開始學(xué)習(xí)中國歷史。I’ve been studying for over two years now.我已經(jīng)學(xué)習(xí)兩年了。(現(xiàn)在完成進行時)9 9.For a foreigner like me, the more I learn about Chinese history, the more I enjoy living in China.對于一個象我這樣的外國人來說, 了解中國歷史越多, 我越喜歡住在中國。10.the more I learn about Chinese history, the more I enjoy living in China.the +比較級……, the +比較級…… 越……越…… 你學(xué)習(xí)越認(rèn)真, 你的成績就會越好.

      The harder you study, the better your grades will be.11.Although I live quite far from Beijing, I’m certain I will be here for the Olympic Games in 2008!quite adv.相當(dāng);十分

      quite far from

      距離……相當(dāng)遠 certain

      adj.確實的;無疑的 be certain 確信……, 肯定…… =be sure the Olympic Games 奧林匹克運動會

      12.自便。You ______ _____ to come and go as you please.13.If you know where she is,please________(告之我)14.We have_______(用盡)money to buy the house.15.Tom _______(對……感興趣)science ten years ago.16.He would like to ______(交些朋友)in China.17.The poor man had to________(謀生)by begging.

      第二篇:新目標(biāo)八下unit3全英教案

      為您提供初中英語教學(xué)資源

      Unit 3: What were you doing when the UFO arrived?

      I.Analysis of the Teaching Material 1.Teaching Aims and Demands(1)Knowledge Objects: In this unit students learn to talk about past events and to tell a story.(2)Ability Objects: To train the students’ ability of listening, speaking, reading and writing.(3)Moral Objects: To be virtuous is to do good.Virtue is fairer than beauty.2.Teaching Key Points: Introducing the key vocabulary and target language.3.Teaching Difficulties: New language ? I was standing in front of the library when the UFO landed.While the alien was buying a key ring, I called the police.? UFO, alien, took off, landed, arrived, bathroom, bedroom, kitchen, barber's chair, barber shop, standing, studying, cleaning, talking, cutting, cooking, eating, getting out, bought, got out, making, sleeping, buying, while, when II.Teaching Time: Six periods Section AAdditional materials to bring to class

      ? paints or markers and large paper for a class mural Language goal ? Ask one student to leave the room and wait outside the door.Then ask different students to start doing different things.One student can walk around the room.Another can look out of the window.A third can stand on his or her chair.Ask all three students to continue doing what they are doing without stopping and then ask the student outside the door to come in.? Ask the student outside the door to come in and sit down.Then ask the three students who were walking around the room, looking out the window, and standing on a chair to sit down.? Ask the first student who was doing an action, What were you doing when(student A)walked in? Help him or her to answer(supplying the whole answer if necessary), / was walking around the room when(student A)walked in.Ask die class to repeat, He(She)was walking around the room when(student A)walked in.? Repeat this with the second and third students who were doing actions: / was looking out the window when(student A)walked in.Ask the class to repeat, He(She)was looking out the window when(student A)walked in.The third student says, 1 was standing on a chair when(student A)walked in.Ask the class to repeat, He(She)was standing on a chair when(student A)walked in.? Ask some other students the question.What were you doing when(student A)walked in? They may answer.-/ was sitting here when(Student A)walked in or/ was talking to Carlos when(Student A)walked in.1 a This activity introduces some key vocabulary.? Point to the sentences.Say each sentence to the class and ask the students to repeat it-Ask-students to explain what each one means.They can use actions and simple explanations.For example, for in the bathroom, a student can pretend to he brushing his or her teeth or taking a shower and say, 1 was in the bathroom.I was brushing my teeth or I was in the bathroom.I was taking a shower.For barber shop and barber's chair, you may want to draw simple pictures on the

      為您提供初中英語教學(xué)資源

      hoard showing two barber chairs in a barber shop with a barber cutting a boy's hair.? Point out the six people and read the letter next to each one.Then ask students to write the letter of each person in the write-on line in front of each sentence.? Point out the sample answer.? Correct the answers.b This activity gives students practice in understanding the target language in spoken conversation.? Read the instructions.? Point to the people in the picture in activity la.Say, You will hear a recording of a reporter talking to the people in this picture.? Point to the two phrases after each letter in this activity.Say, There are two phrases after each letter.Listen carefully and circle the phrase that tells what each person was doing.Point out the sample answer.? Play the recording the first time.Students only listen

      ? Point to the people in the picture as you hear about that person on the recording.? Play the recording a second time.This time ask students to circle the correct phrases.? Correct the answers.c This activity provides guided oral practice using the target language.? Read the instructions.? Point out the example in the sample dialogue.Ask two students to read it to the class.? Say, Now work with your partner.Start by reading the conversation in the box with your partner.The look at the other people in the picture and have conversations about these people.You can use words and phrases from activity 1b.? As they talk, move around the room checking their work.Offer language support as needed.? Ask several pairs of students to say their conversations to the class.2a This activity gives students practice in understanding the target language in spoken conversation.? Read the instructions.? Point to the sentences with write-on lines.Say, You will hear a recording of a reporter talking to several people.Please put a number I in front of the thing that happened first, a number 2 in front of the thing that happened second, and so forth.? Play the recording the first time.Students only listen.Point to the sentences.? Play the recording a second time.This time ask students to write the numbers in front of the correct phrases.? Correct the answers.2b This activity provides listening and writing practice using the target language.? Read the instructions.Point to the write-on lines in each sentence.? Play the recording.Ask students to write the word when or while on each line.? Play the recording again.Ask students to correct their answers.Grammar note Point out that the abbreviation UFO means Unidentified Flying Object—something that is flying through the air that is unknown(unidentified)here on earth.Say Many abbreviations using two or three letters have a period after each letter For example, N.Y means New York and M.D.means Medical Doctor.But some abbreviations do not use periods.We usually write the abbreviation UPO without periods.2c This activity provides guided oral practice using the target language.? Point out the picture.Ask students to say what each person is doing.? Read the instructions.Then point 10 the example in the sample dialogue-Ask three students to

      為您提供初中英語教學(xué)資源

      read it to the class.Say, Make conversations like this about the people in the picture.? Ask students to work in small groups.Move around the room checking the progress of the groups and offering help as needed.? Ask a group to say its conversation to the class.Grammar focus ? Review the grammar box.Ask students to say the two forms of each statement.? Repeat the activities from the Language Goal section at the beginning of this unit using different students and different actions.For example, have a different student wait outside the door.Have three students in the classroom read a book, sit on the floor, and draw a picture on the board.? Ask the student outside the door to come in and sit down.Then ask the three students who were reading a hook, sitting on the floor, and drawing a picture to sit in their chairs.? Ask the first student who was doing an action, What were you doing when(student A)walked in? Guide him or her to answer, 1 was reading a book when(student A)walked in.Ask the class to repeat.He(She)was reading a book when(student A)walked in.? Repeat this with the second and third students who were doing actions.? Draw a long horizontal line across the board.Write the words / was drawing a picture on the line.Then make a star in the middle of the line and write the word's when(student A)walked in below the star.Point to the straight line and say This action continued for a long time.Then point to the star and say, This action happened quickly.Run your finger along the line as you say the words, I was drawing a picture.Then slap your hand on the board at the star as you say the words, when(student A)walked in.? Point out that the word when comes before a quick action that happens only once.The word while comes before an action that continues for some time.? Ask students to say other sentences with when and while from this unit(or from their own lives).Optional activity Describe an action that you did earlier in the day and that took only a moment to do and tell what time it happened.For example,/ ate and listened to the news at 7:00 this miming, Then ask students to tell what they were doing at that time using the words when and while.Help the students make the first few students make sentences like these: / was sleeping when he/she listened to the news.or When he/she was listening to the radio, I was eating breakfast.Then describe similar actions at different times and ask students to make sentences using when and while.3a This activity provides reading and grammar practice using the target language.? Read the instructions.? Look at the pictures with the students.Ask them to describe what is happening in each one.? Ask students to complete the work on their own.? Correct the answers.3b This activity presents an opportunity for students to measure their vocabulary production against their comprehension.Students may understand what they read, but it is also important that they be able to tell others what they understand.? Read the instructions.? Ask one or two students to epxiain what is happening in one of the pictures.為您提供初中英語教學(xué)資源

      Encourage them with additional vocabulary they may have forgotten.? Ask students to complete the work in pairs.Remind them to use as many details as possible in their stories.Students may also add new details.? Ask a few students to tell their stories to the class.Encourage students to add details.4

      This activity encourages students to use times to discuss their own experiences.? Read the instructions.? Ask two students to read the sample dialogue.? Ask another one or two students to talk about what they did at different times.You may use times and days other than the ones listed in the exercise.? Ask students to complete the work in groups.Students list and discuss their different activities.? Ask a few students to share their lists.Ask a few students to talk about their day in a conversation.Homework: Review Section A.Recite the words in this unit.Preview Section B.Finish Exx.Section A.Section B New language ? shouted, shouting, took a photo, scared, police officer, call the police, newspaper reporter, climbed, climbing, jump down, couldn't, another, station, crowded, found, happened, ran away 1 This activity introduces some key vocabulary.? Point to the pictures and ask students to say what they see.Provide key vocabulary words as needed.Repeat incomplete or incorrect sentences in full,correct form.[T = Teacher, S = student] T: What is the cat doing? Sl: Going up the tree.T: That's correct.The cat is climbing the tree.It's climbing the tree.Class repeat.It's climbing the tree.SS: It's climbing the tree.? Read the instructions, say, Write the letter of each picture in front of the correct sentence.? Point out the sample answer.Ask students to finish the work on their own.? Correct the answers.2a This activity gives students practice in understanding the target language in spoken conversation.? Read the instructions.? Point to the phrases in the chart.Say, You will hear a recording of two people talking.They will talk about some of these things.They will not talk about two of these things.Check the things they talk about.Point out the sample answer.? Play the recording the first time.Students only listen.? Play the recording a second time.This time ask students to check the phrases they hear on the recording.? Correct the answers.2b This activity gives students practice in understanding the target language in spoken conversation.? Read the instructions.Say, This time you will be listening only for who did each thing.? Point to the third column in activity 2a.Point out the sample answer.Ask students what that answer means(It means that item 1 in activity la [saw a cat in a tree] matches with item e in activity 2a []ohn1.)Say, John saw a cat in a tree.為您提供初中英語教學(xué)資源

      ? Play the recording.Ask students to write the correct fetter after the actions they checked in activity 2a.? Play the recording a second time, if necessary.? Correct the answers.2c This activity provides guided oral practice using the target language.? Read the instructions.Say, One student will start the sentence and the other student will finish it.? Point to the example in the sample dialogue.Ask two students to read it to the class.? Ask students to work in pairs.Move around the room checking progress and offering help as needed.? Ask several pairs to say some of their sentences to the class.Optional activity

      Some students may be ready to do a more advanced form of this activity.Ask these pairs of students to make up true sentences about their lives starting with the word while.For example, they can talk about what they were doing yesterday afternoon.One might say, While I was walking home yesterday afternoon...The other could say, While I was walking home yesterday afternoon, I saw a big dog.3 This activity provides reading and writing practice using the target language.? Read the instructions, pointing to the article and the list of questions.? Ask students to say what they see in the picture.Accept any reasonable answers.Rephrase any incomplete answers or answers with incorrect language as complete.correct sentences.For example: T: what do you see in the picture?S1: Suitcase.T: That's correct.There's a suitcase in the picture.What else is in the picture?S2: A woman.T: Correct.There's a woman.Where is she?S3: Train station? T: Yes, there's a woman at a train station.? Ask students to read the article to themselves, circling any words or phrases they don't understand.Explain these words or phrases or ask other students to do this.? Read the article to the class.Answer any other questions students may have.? Point to the list of five questions.Ask students to write tile answers.? Correct the answers.4a This activity presents an opportunity for students to engage in open-ended writing.? Read the instructions.? Ask one or two students to explain what is happening in one of the pictures.Be careful not to ask for too many descriptions or the other students will not have to think about their answers.? Ask students to complete the work on their own.Remind them to use times in their stories.? Ask a few students to read their stories.Ask if some students have different stories.If not, suggest different endings.For example, The girl's brother found her bike and thought she had forgotten it there.4b This activity lets students practice their speaking an listening skills in role plays.? Read the instructions.Students work in pairs with two students at a time playing the role of police officer and bicycle thief.? Ask students to complete the work on their own.? Ask a few students to show their role plays to the class.Ask the students to vote on the best role play.Homework: Review this unit.Finish Exx.Section B.Recite 3a Writing: Predicting your future, including your future job, the city you will live, etc.Preview the next unit.

      第三篇:浙教版 八下 教案 全

      學(xué)智教育

      浙 教 版 教 案

      (八年級下)

      第一章:粒子的模型與符號 第1節(jié)

      模型、符號的建立與作用

      教學(xué)目標(biāo)

      1、體驗使用符號、建立模型的思想。

      2、能用物質(zhì)粒子模型來解釋物質(zhì)的三態(tài)變化。重點難點分析 體驗使用符號與建立模型的思想

      課程資源的準(zhǔn)備與開發(fā) 地球儀、PPT圖片、細胞模型 教 學(xué) 預(yù) 設(shè) 調(diào) 控 對 策

      【引入】回憶以前學(xué)習(xí)中,曾用用過的符號(略)?!居懻摗繛槭裁匆褂眠@些符號?用這些符號來表示實物? 【板書】

      一、符號

      用符號能簡單明了地表示事物,可避免由于事物外形不同和表達地文字語言不同而引起地混亂。

      【引語】除了符號,我們還使用模型,請舉例。

      如地球儀、細胞模式圖、眼球模型等。【討論】為什么要使用這些模型呢?

      學(xué)智教育

      1、因為地球太大,難以認(rèn)識,所以人們常用地球儀。

      因為細胞太小,難以觀察,所以人們畫出了細胞模式圖。

      由于眼球構(gòu)造太復(fù)雜,難以表達,人們制造了眼球模型。

      2、讀圖:

      液態(tài)水與氣態(tài)水的狀態(tài)模型 通過讀圖,可知:

      一、水在三態(tài)變化中,分子沒有發(fā)生變化;

      二、水在三態(tài)變化中,分子間的距離發(fā)生了變化。

      3、建立模型的意義:

      可以幫助人們認(rèn)識和理解一些不能直接觀察到的事物。

      4、模型的不同表示方法: 【練習(xí)】

      【補充】元素符號的記憶和書寫?!抉R龍老師備課】

      【引入】在我們已經(jīng)學(xué)完的三冊科學(xué)書里,我們接觸了很多新的東西。例如:

      運動學(xué):v

      t

      s

      電學(xué):R

      I

      U

      單位:m/s

      s

      m

      單位:Ω

      A

      V 請同學(xué)用一個次來概括一下以上的內(nèi)容,可見這些都是一些符號 【新授】

      一、請同學(xué)說出日常生活中常見的符號

      二、請同學(xué)門討論為什么要使用這些符號?

      講解:例如時間,不同國家用不同的文字表示,為了減少這種語言文化帶來的差異,我們就用T來表示時間,再如一些復(fù)雜的事物,如電路圖中的元件,如果都要用實物表示,那么電路圖會變的十分復(fù)雜,所以我們就用一些簡單的符號表示,可見 符號的作用:

      1、簡單的表明事物

      2、避免混亂

      學(xué)智教育

      三、模型

      1、請同學(xué)描述一下對地球的認(rèn)識

      2、請同學(xué)在地球儀上找到一些相應(yīng)的位子,并描述一下。

      3、同學(xué)們都知道,任何生都是由細胞構(gòu)成的,請同學(xué)說一下動物細胞和植物細胞的區(qū)別。

      畫出細胞模式圖

      再請一位同學(xué)根據(jù)細胞模式圖來分析一下動物細胞和植物細胞的區(qū)別。

      4、眼球的結(jié)構(gòu)很復(fù)雜,所以我們通常用人們制造的眼球模型來認(rèn)識其結(jié)構(gòu)

      5、請同學(xué)們填寫書本第二頁的填空

      地球儀、細胞模式圖、眼球模型就是用模型來表示一些我們通過肉眼直接很難觀察很難認(rèn)識清楚的對象時采用的方法,所以從某種意義上講符號也是一種模型。

      四、請問同學(xué)水有幾種狀態(tài)?

      水用符號表示為“H2O”也就是說它由兩個氫原子,一個氧原子構(gòu)成,用模型表示水分子

      從三態(tài)說明三種模型(略)

      請同學(xué)在書上填空

      通過模型,我們可以直觀的區(qū)分出水的三態(tài),從模型中我們也可以知道水在三態(tài)中,分子沒有發(fā)生變化,變化的是分子間的距離,需要強調(diào)一點,一個模型可以是一張圖,一個物體,也可以是對一個復(fù)雜的對象或過程的 示意,如光合作用,我們將光合作用過程中物質(zhì)的變化概括的寫成一個簡單的表達式就是一個模型,包括我們以后要學(xué)的化學(xué)方程式都是模型。五,綜述

      通過學(xué)習(xí)同學(xué)們應(yīng)該建立一種使用符號和模型的思想,它可以幫我們形象的認(rèn)識事物的共同點,免去一些外因的科學(xué)研究是一個由具體到抽象,再由抽象到具體的過程符號和模型就是中間的紐帶,所以我們建立了模型和符號的概念對我們以后學(xué)習(xí)科學(xué),研究科學(xué)是很有利的,同學(xué)們通過學(xué)習(xí)后經(jīng)常去使用一些符號和模型,也可以去設(shè)計一些符號和模型,只要方便使用就可以。當(dāng)然你設(shè)計的符號如果沒有經(jīng)過有關(guān)機構(gòu)的認(rèn)同,千萬不要公開發(fā)表!包括你的作業(yè)和試卷。

      學(xué)智教育

      第2節(jié)

      物質(zhì)與微觀粒子模型

      教學(xué)目標(biāo)

      1、知道物質(zhì)是由分子構(gòu)成的,分子是由原子構(gòu)成,物質(zhì)也可由原子直接構(gòu)成。

      2、知道原子組成分子時結(jié)構(gòu)和種類不同,物質(zhì)的性質(zhì)也不同。

      3、認(rèn)識分子微粒的大小、質(zhì)量的數(shù)量級。重點難點分析 重點:知道物質(zhì)的不同構(gòu)成:分子、原子和離子。

      知道物質(zhì)構(gòu)成與性質(zhì)的關(guān)系。難點:認(rèn)識微粒的數(shù)量級的大小。

      課程資源的準(zhǔn)備與開發(fā) 用橡皮泥和牙簽讓學(xué)生制作分子模型 實驗:稱量米的質(zhì)量 教 學(xué) 預(yù) 設(shè) 調(diào)控對策

      【復(fù)習(xí)】你對分子的了解有多少?

      --物質(zhì)由分子構(gòu)成;分子在不停地運動;分子間有間隙;

      【引入】分子又是由什么粒子構(gòu)成的呢?

      【分析】水電解實驗:說明水是由氫、氧元素組成; 水分子是由更小的粒子構(gòu)成的--原子構(gòu)成。由這個實驗還可以知道:

      1、分子和原子的區(qū)別:在化學(xué)變化中,分子可分,原子不可再分。

      2、化學(xué)變化的實質(zhì):分子分割成原子,原子重新組合成新的原子。

      3、化學(xué)變化和物理變化的本質(zhì)區(qū)別:在變化中,物質(zhì)的分子變成了其它物質(zhì)的分子,就是化學(xué)變化。在變化中,物質(zhì)的分子還是原來的分子,只是分子間的距離發(fā)生了變化,就是物理變化。

      學(xué)智教育

      【介紹】人類對原子的認(rèn)識歷程。(資料打?。?/p>

      【讀圖】我們用模型來認(rèn)識分子、原子,表示化學(xué)反應(yīng)過程?!窘Y(jié)論】

      一、物質(zhì)--分子--原子

      宏觀--微觀----物質(zhì)組成的層次性 【了解】不同的物質(zhì)由不同的微粒構(gòu)成。

      金屬由原子構(gòu)成;石墨由碳原子組成;

      --說明哪些物質(zhì)是由原子直接構(gòu)成的:金屬和固體非金屬

      二、不同種類的物質(zhì)

      【讀圖】【思考】不同物質(zhì)的模型

      (1)構(gòu)成分子的原子可以是同種原子,也可以是不同種原子。

      (2)同種原子構(gòu)成不同物質(zhì)時結(jié)構(gòu)是不一樣的。--金剛石中碳原子的排列成網(wǎng)狀,石墨中碳原子的排列成層狀,足球烯中碳原子的排列成球狀。重點講解:金剛石和石墨在性質(zhì)上的區(qū)別: 物理性質(zhì)上:硬度、導(dǎo)電性、熔點、沸點等;

      化學(xué)性質(zhì)上:一樣?!九e例】科學(xué)家做過的實驗:在密閉的容器中充滿氧氣,分別放入金剛石和石墨,結(jié)構(gòu)都生成唯一的產(chǎn)物--二氧化碳。

      三、粒子的大小與質(zhì)量

      1、分子和原子都有一定的質(zhì)量和體積.原子的體積很小,半徑的數(shù)量級在10-10米。原子的質(zhì)量也非常小,數(shù)量級在10-26千克。

      2、不同質(zhì)量的原子質(zhì)量不同,體積也不同?!菊J(rèn)識】不同的分子和原子質(zhì)量。

      【學(xué)生活動】感受10-27千克質(zhì)量大小。稱量1克米,數(shù)出米的粒數(shù)?!狙a充】

      學(xué)智教育

      第3節(jié)

      原子結(jié)構(gòu)的模型

      教學(xué)目標(biāo)

      1、了解原子的構(gòu)成、原子結(jié)構(gòu)模型及其在歷史上的發(fā)展過程,體驗建立模型的思想。

      2、了解同位素的結(jié)構(gòu)特點,能說出1-2項在實際生活中的用途

      3、知道物質(zhì)也可由離子構(gòu)成,認(rèn)識離子微粒大小的數(shù)量級。重點難點分析 重點:了解原子的構(gòu)成、原子結(jié)構(gòu)模型及其在歷史上的發(fā)展過程,體驗建立模型的思想。難點:對原子結(jié)構(gòu)知識的初步了解 課程資源的準(zhǔn)備與開發(fā) 實驗,課外資料

      調(diào)控對策 教 學(xué) 預(yù) 設(shè)

      【作業(yè)講評】:摩擦起電的原因:物體中本來就存在正電荷和負電荷,通常情況下正負電荷的數(shù)量相等,物體是中性的。當(dāng)兩個物體摩擦?xí)r,電子從束縛較弱的物體轉(zhuǎn)移到另一物體。失去電子的物體帶正電,得到電子的物體帶負。注意:摩擦起電都是帶負電的電子轉(zhuǎn)移,而不是帶正電的正離子或質(zhì)子等的轉(zhuǎn)移?!疽搿?/p>

      1、練習(xí):由同種原子構(gòu)成的物質(zhì)是純凈物;

      由不同種原子構(gòu)成的物質(zhì)是混合物;

      分子是由不同種原子構(gòu)成的。

      2、復(fù)習(xí):物質(zhì)的構(gòu)成、電流的形成 【新授】

      一、原子結(jié)構(gòu)模型的建立與修正

      1、道爾頓--實心球原子結(jié)構(gòu) --發(fā)現(xiàn)原子

      學(xué)智教育

      2、湯姆森--“湯姆森模型”:原子是一個平均分布著正電荷的球體,帶負電荷的電子嵌在中間。

      --發(fā)現(xiàn)電子

      3、盧瑟福--“盧瑟福模型”:電子繞原子核運行 【介紹】實驗:α粒子轟擊原子

      4、波爾--“分層模型”:電子在固定的軌道上運動

      5、“電子云模型”--電子在核周圍有的區(qū)域出現(xiàn)的次數(shù)多,有的區(qū)域出現(xiàn)的次數(shù)少,就象“云霧”一樣籠罩在核的周圍。

      【小結(jié)】建立模型是一個不斷完善、不斷修正的過程。使學(xué)生體驗、學(xué)習(xí)科學(xué)家提出問題、建立假設(shè)、修正模型的研究方法。

      二、原子的結(jié)構(gòu):

      1、原子:

      原子核:

      帶正電(不顯電性)

      核外電子:帶負電

      2、原子核大小與核外電子運動范圍(原子大小)的比較。

      三、揭開原子核的秘密

      1、原子核是由更小的兩種粒子質(zhì)子和中子構(gòu)成的。

      核電荷數(shù):原子核所帶的電荷數(shù)

      一個電子帶一個單位的負電荷,一個質(zhì)子帶一個單位的負電荷;

      【讀表】思考:在原子中哪些數(shù)目總是相等的?(1)核電荷數(shù)=質(zhì)子數(shù)=核外電子數(shù)。(2)中子數(shù)不一定等于質(zhì)子數(shù)。(3)原子內(nèi)可以沒有中子。

      2、質(zhì)子、中子核電子的質(zhì)量比較

      質(zhì)子、中子的質(zhì)量大小幾乎相等。電子質(zhì)量很小,在整個原子的質(zhì)量中所占的比例極小,可忽略不計。所以說,原子的質(zhì)量主要集中在原子核上。

      學(xué)智教育

      【讀圖】一杯水的微觀層次分析

      3、一杯水--水分子--氧原子、氫原子--原子核、核外電子--質(zhì)子、中子--夸克

      四、原子的“孿生兄弟”--同位素

      1、具有相同的核電荷數(shù)(即質(zhì)子數(shù))的同一類原子的總稱為元素。如:氧元素就是所有氧原子的總稱。

      同種原子的原子核內(nèi)核電荷數(shù)、質(zhì)子數(shù)與中子數(shù)是一定的。但有的原子其核內(nèi)的中子數(shù)會發(fā)生變化。

      【舉例】氧的三種原子的原子核:核內(nèi)都有8個質(zhì)子,但中子數(shù)分別是8個、9個、10個。屬于同種元素的不同原子。

      2、原子中原子核內(nèi)質(zhì)子數(shù)相同、中子數(shù)不相同的同類原子統(tǒng)稱為同位素。氧的同位素原子是氧元素的不同種原子。

      【思考】氧的3種同位素其核外電子應(yīng)各有幾個?--8個。如:氫有3種同位素原子:氕、氘、氚。汞有7種同位素。

      3、同位素元素在工業(yè)、農(nóng)業(yè)、醫(yī)療、國防等方面有廣泛的應(yīng)用:化學(xué)分析、消除細菌、醫(yī)學(xué)診斷等。

      【閱讀】利用碳-14同位素測定年代

      五、帶電的原子--離子 【實驗】鈉在氯氣中燃燒的實驗

      實驗現(xiàn)象:

      鈉原子失去電子--形成正電荷的鈉離子(陽離子)氯原子得到電子--形成負電荷的氯離子(陰離子)

      所以,離子就是帶電的原子或原子團(離子的組成元素不止一種)。離子和分子、原子一樣也是構(gòu)成物質(zhì)的基本粒子?!緦W(xué)生實驗】估計高錳酸鉀離子的大小 說明:這是一個思想實驗。

      學(xué)智教育

      目的:讓顯示感受到離子的存在,利用簡易可行的實驗估計構(gòu)成物質(zhì)的粒子--離子大小的數(shù)量級。

      基本操作技能:固體藥品的取用;毫米刻度尺的使用;液體體積的測量;振蕩。主要科學(xué)方法:估計方法、觀察實驗方法、對比方法。

      實驗設(shè)計思路:已知經(jīng)過多次按1/10稀釋后,最后能看到的紫紅色高錳酸鉀溶液中,每100毫升大約存在1000個高錳酸鉀離子。根據(jù)稀釋的次數(shù)克推算出高錳酸鉀晶體中含有的高錳酸鉀離子數(shù)為N。溶解前,先用毫米刻度尺測量并估算出離子的大小,這是一種通過宏觀現(xiàn)象推測微觀世界的思想方法。

      學(xué)智教育

      第4節(jié)

      組成物質(zhì)的元素

      教學(xué)目標(biāo)

      1、知道自然界的物質(zhì)由100多種元素組成,從組成物質(zhì)元素角度出發(fā)理解物質(zhì)初步分類思想。

      2、知道組成人體、地球的主要元素。重點難點分析 重點:單質(zhì)和化合物的概念 難點:區(qū)別單質(zhì)、化合物、混合物 課程資源的準(zhǔn)備與開發(fā)

      教 學(xué) 預(yù) 設(shè) 調(diào) 控 對 策

      【引入】講人類認(rèn)識微觀世界的歷史 【新授】

      一、元素的種類 1、110多種,包括人造元素。

      元素分類:金屬元素和非金屬元素(包括稀有氣體元素:在自然界含量極少,性質(zhì)非常穩(wěn)定)

      2、單質(zhì):由同種元素組成的純凈物。舉例:氧氣、金屬鐵等?;衔铮河刹煌N元素組成的純凈物。舉例:二氧化碳、水等?!咀⒁狻繂钨|(zhì)和化合物的區(qū)別及分類依據(jù)

      【閱讀】元素名稱的由來:進一步來了解元素的分類

      二、元素的分布

      1、元素在地殼的分布是不均勻的,地殼主要由氧、硅、鋁、鐵、鈣、鈉、鉀、鎂、氫等元素組成。其中含量最高的是氧,其次是硅。金屬元素中含量最高的是鋁,其次是鐵。

      2、在人體中含量最高的是氧元素,其次是碳、氫; 【閱讀】人體種元素的作用

      【校本課程】營養(yǎng)與各元素的攝?。粡V告與生活

      3、在海水中除了水由氫氧兩種元素組成以外,含量較高的是氯元素和鈉元素(氧85.5%,氫10.7%,氯2.0%,鈉、鎂等1.5%),還有貴重的金屬等--海洋是資源寶庫,21世紀(jì)是“海洋

      學(xué)智教育 的世紀(jì))。

      【課外探究】海水中氕、氘、氚的利用

      4、生物所含的大量的有機化合物如血糖、植物纖維主要由碳、氫和氧三種元素組成的。

      5、人造元素通過核反應(yīng)制得的,其中一部分人造元素核天然元素具有放射性。有利有弊:對人體有害;利用放射性可以治療一些疾病。

      第5節(jié)

      表示元素的符號

      教學(xué)目標(biāo)

      日 期

      1、認(rèn)識常見元素符號(H、0、C、S、Si、Na、Fe、Cu、Cl、Ca、Ag、Al、I、K、P),學(xué)智教育

      會查閱元素符號。

      2、通過探究活動,初步認(rèn)識元素周期表,知道金屬元素和非金屬元素在元素周期表中的分布。

      3、閱讀元素周期表的發(fā)現(xiàn)及應(yīng)用的地形、典型歷史事實,體會科學(xué)家的創(chuàng)造性思維和元素周期表的重要意義。

      重點難點分析 重點:認(rèn)識常見元素符號

      難點:元素周期表的認(rèn)識和簡單運用

      課程資源的準(zhǔn)備與開發(fā)

      教 學(xué) 預(yù) 設(shè) 調(diào) 控 對 策

      【復(fù)習(xí)】元素的種類、分布以及與物質(zhì)、原子、分子間的關(guān)系 【新授】

      一、元素符號

      1、元素符號是國際上統(tǒng)一采用的符號,通常用該元素拉丁文的第一個大寫字母來表示。當(dāng)元素的第一個字母與其它元素重復(fù)時,克寫上該元素名稱的第二個字母以示區(qū)別。

      2、元素符號一般表示: ⑴一種元素

      ⑵這種元素的1個原子 ⑶這種元素的原子的質(zhì)量

      【練習(xí)】“2N”等的意義;與“N2”的區(qū)別

      二、元素周期表

      【介紹】簡單介紹元素周期表

      7個周期(短周期、長周期、不完全周期); 16個族(7個主族、7個副族、0族、第8族); 112種元素(金屬元素、非金屬元素、稀有元素); 【探究】尋找元素周期表中元素之間的聯(lián)系和規(guī)律

      1、提出問題:

      學(xué)智教育

      2、建立假設(shè):規(guī)律可能表現(xiàn)在元素的性質(zhì)上; 規(guī)律可能表現(xiàn)在元素的種類上; 規(guī)律可能表現(xiàn)在元素的質(zhì)量上; 規(guī)律可能表現(xiàn)在元素的質(zhì)子數(shù)上; 規(guī)律可能表現(xiàn)在元素的中子數(shù)上; 規(guī)律可能表現(xiàn)在元素的發(fā)現(xiàn)史上;

      3、設(shè)計方案:研究課本上的元素周期表

      4、記錄考察結(jié)構(gòu)

      5、驗證假設(shè)

      6、交流 【小結(jié)】

      第6節(jié)

      表示物質(zhì)的符號

      教學(xué)目標(biāo)

      1、會查元素的化合價,會運用化合價寫出簡單的化學(xué)式。

      2、能解釋化學(xué)式表示的意義,能根據(jù)化學(xué)式區(qū)分單質(zhì)和化合價、金屬和非金屬。

      3、能用;表示離子或帶電原子團。

      重點難點分析 重點:會查元素的化合價,會運用化合價寫出簡單的化學(xué)式。難點:會運用

      學(xué)智教育

      化合價寫出簡單的化學(xué)式。課程資源的準(zhǔn)備與開發(fā)

      教 學(xué) 預(yù) 設(shè) 【復(fù)習(xí)】

      1、默寫元素符號

      2、說明符號的意義 【新授】

      一、化學(xué)式

      1、用元素符號來表示物質(zhì)分子組成的式子稱化學(xué)式

      2、化學(xué)式的確定依據(jù):由實驗測定組成,如水的電解實驗測定水的組成。不能憑空想象,一種物質(zhì)只有一種化學(xué)式。

      3、化學(xué)式的書寫原則 ⑴單質(zhì)化學(xué)式的寫法: 雙原子分子: 稀有氣體: 多原子分子:

      固態(tài)非金屬(結(jié)構(gòu)復(fù)雜,習(xí)慣上用元素符號表示): 金屬(同上):

      ⑵化合物化學(xué)式的寫法:按一定順序?qū)懗鼋M成化合物的所有元素符號,然后在每種元素符號的右下角用數(shù)字寫出化合物分子中該元素的原子個數(shù)。

      一定順序:氧元素與另一種元素組成的化合物,一般要把氧元素符號寫在左邊;氫元素與另一元素組成的化合物,一般要把氫元素寫在左邊;金屬元素、氫元素與非金屬元素組成的化合物,一般要把非金屬元素寫在右邊。

      直接由離子構(gòu)成的化合物,其化學(xué)式常用其離子的最簡單整數(shù)比表示?!纠?【練習(xí)】 調(diào) 控 對 策

      學(xué)智教育

      4、化學(xué)式的讀法:一般從右向左讀做“某化某”;或者要指出一個分子里的個數(shù)。

      5、化學(xué)式表示的意義: ⑴表示某種物質(zhì)(純凈物)⑵表示某種物質(zhì)的一個分子 ⑶表示物質(zhì)的元素組成 ⑷表示物質(zhì)分子的構(gòu)成 ⑸表示分子的質(zhì)量 【例】 【練習(xí)】 【補充】

      1.化學(xué)式能代表某種質(zhì),如CO2這個化學(xué)式就代表二氧化碳。因為一種物質(zhì)只用一個化學(xué)式來表示。

      2.化學(xué)式能表示物質(zhì)組成。如H2O這個化學(xué)式能表示出水是由氫元素和氧元素組成。

      3.化學(xué)式能表示物質(zhì)中原子或離子個數(shù)比。如NaCl這個化學(xué)式表示在氯化鈉中氯離子和鈉離子的個數(shù)比為1∶1。

      4.通過化學(xué)式可計算式量。如水的化學(xué)式是H2O,H2O的式量=1×2+16=18

      5.通過化學(xué)式可計算組成物質(zhì)的各元素的質(zhì)量比。如二氧化硫中硫元素和氧元素的質(zhì)量比等于:32:16×2=1∶1

      6.通過化學(xué)式可計算物質(zhì)中某一元素的質(zhì)量分?jǐn)?shù)。

      二、離子的符號

      【引入】當(dāng)原子失去或得到電子成為離子時,怎樣用符號來表示呢?

      1、離子符號是在形成該離子的原子的元素符號右上角標(biāo)出該離子所帶的電荷數(shù)。

      2、離子符號的意義:

      3、常見的離子(包括原子團所帶的電荷數(shù))

      三、化合價

      1、原子之間相互化合的數(shù)目,用化合價來表示。

      學(xué)智教育

      2、常見化合價:

      金屬元素、非金屬元素,氫、氧元素的化合價規(guī)律; 常見原子團(根)的化合價。

      3、原則:在化合物中所有元素化合價的代數(shù)和為零。

      4、單質(zhì)的化合價為零。

      5、標(biāo)價方式與離子表示方式。

      6、應(yīng)用:

      根據(jù)化合價的代數(shù)和為零推出各元素的化合價; 根據(jù)化合價寫出化合物的化學(xué)式?!纠?/p>

      第7節(jié) 元素符號表示的量

      教學(xué)目標(biāo)

      1、會查閱相對原子質(zhì)量表。

      2、能根據(jù)化學(xué)式計算物質(zhì)的相對分子質(zhì)量。

      3、能根據(jù)化學(xué)式計算元素含量、所含元素質(zhì)量比。

      重點難點分析 重點:能解釋化學(xué)式表示的意義;相對原子質(zhì)量的了解及查閱;根據(jù)化學(xué)式計算相對原子質(zhì)量和元素的質(zhì)量比。

      難點:根據(jù)化學(xué)式計算相對原子質(zhì)量和元素的質(zhì)量比。課程資源的準(zhǔn)備與開發(fā) PPT課件

      學(xué)智教育

      教 學(xué) 預(yù) 設(shè) 【引入】

      今天我們要來學(xué)習(xí)元素符號表示的量,首先請同學(xué)們回憶一下“C”表示的意思

      表示碳元素

      C

      表示一個碳原子

      表示碳元素的質(zhì)量

      關(guān)于前面兩層意思我們已經(jīng)進行了詳細的分析和討論,今天我們就來研究一下其中的第三層含義 【新授】

      我們知道“C”這個元素符號可以表示一個碳原子的質(zhì)量,且由相關(guān)的表中可以查得

      C:1.993×10-26千克

      H: 1.674×10-27千克

      O: 2.657×10-26千克

      由此可見,原子的質(zhì)量非常小,所以直接用它的真實質(zhì)量會使計算復(fù)雜,且數(shù)據(jù)不容易記憶,所以我們?nèi)∷麄兿鄬Φ闹怠T谌∵@個相對的值之前我們必須先有一個標(biāo)準(zhǔn)。就像畫地圖時用的比例尺,我們就可以把一個國家按比例縮小畫到一張紙上,現(xiàn)在我們的原子質(zhì)量太小了,所以我們要讓它按比例擴大,而且擴大后的數(shù)值要盡可能易記,實際上這就是建立原子質(zhì)量模型。找出了原子質(zhì)量的標(biāo)準(zhǔn),我們就把其它原子的質(zhì)量與之相比,把比值就定義為某元素的相對原子質(zhì)量。下面就來規(guī)定這個標(biāo)準(zhǔn)

      C-12(提問:12表示什么意思?表示質(zhì)子數(shù)和中子數(shù)之和是12,由于碳有兩種同位素,即C-12,C-14,所以必須指明是哪種碳原子。)C-12

      M=1.993×10-26千克

      1/12C-12

      M=1/2×1.993×10-26千克=1.661×10-27千克 先留一個問題,為什么要取1/12C-12作為標(biāo)準(zhǔn)?

      找到了標(biāo)準(zhǔn),我們就可以給出任意一種元素的相對原子質(zhì)量了

      學(xué)智教育

      例如:O: 2.657×10-26千克/1.661×10-27千克

      一、相對原子質(zhì)量

      以C-12質(zhì)量的1/12作為標(biāo)準(zhǔn),其它原子的質(zhì)量跟它相比所得的比值,叫做這種原子的相對原子質(zhì)量。

      【練習(xí)】查找各元素原子的相對原子質(zhì)量。

      【閱讀】張青蓮教授與相對原子質(zhì)量--激發(fā)愛國熱情

      二、相對分子質(zhì)量

      1、一個分子中各原子的相對原子質(zhì)量總和就是該原子的相對分子質(zhì)量?!纠}】注意規(guī)范及計算方法。H2SO4、3CO2、CUS04.5H2O等

      2、化學(xué)式的意義:5點(1)表示一種物質(zhì);

      (2)表示組成這種物質(zhì)的元素;(3)表示各種元素原子的個數(shù)比;

      (4)表示這種物質(zhì)的一個分子(對由分子構(gòu)成的物質(zhì))。(5)表示物質(zhì)的相對分子質(zhì)量 【講解】及【練習(xí)】

      三、元素質(zhì)量分?jǐn)?shù)和質(zhì)量比的確定

      1、組成物質(zhì)的各種元素的質(zhì)量比 【例題】H2O、NH4NO3 【練習(xí)】Fe2O3、CO2、H2SO4、NH4HCO3、2、物質(zhì)中某一元素的質(zhì)量分?jǐn)?shù) 【例題】講解例題。

      提醒學(xué)生注意:①各元素的質(zhì)量比跟原子個數(shù)比是不同的。例如NH4NO3中氮、氫、氧三種元素的質(zhì)量比是7∶1∶12,而它們的原子個數(shù)比是2∶4∶3。②計算NH4NO3中氮元素的質(zhì)量分?jǐn)?shù)時,學(xué)智教育

      【練習(xí)】

      【補充】計算5t氧化鐵中含鐵多少噸。[解]氧化鐵的化學(xué)式是Fe2O3 氧化鐵的式量是56×2+16×3=160 5t氧化鐵中所含鐵的質(zhì)量是:5×70%=3.5(t)答:5t氧化鐵中含鐵3.5t。

      復(fù)習(xí)教案

      1、同種原子里

      電量關(guān)系:核電荷數(shù)=質(zhì)子數(shù)=核外電子數(shù) 質(zhì)量關(guān)系:相對原子質(zhì)量數(shù)值=質(zhì)子數(shù)+中子數(shù) 2.同一種元素的離子里

      電量關(guān)系:核電荷數(shù)=質(zhì)子數(shù)≠核外電子數(shù)

      質(zhì)量關(guān)系:相對原子質(zhì)量數(shù)值=質(zhì)子數(shù)+中子數(shù) 3.同一種元素的原子、離子里

      電量關(guān)系:核電荷數(shù)=質(zhì)子數(shù)>核外電子數(shù)

      該微粒為陽離子;

      學(xué)智教育

      核電荷數(shù)=質(zhì)子數(shù)<核外電子數(shù)

      該微粒為陰離子; 核電荷數(shù)-核外電子數(shù)=陽離子的正電荷數(shù)(元素正價數(shù))核外電子數(shù)-核電荷數(shù)=陰離子的負電荷數(shù)(元素負價數(shù))質(zhì)量關(guān)系:與原子、離子相同 4.相對原子質(zhì)量

      元素的相對原子質(zhì)量=某元素一個原子質(zhì)量÷碳原子質(zhì)量的十二分之一?!纠}講解】

      例1:一種四價元素硫化物的式量與此元素氯化物的式量之比為100∶202,確定此元素的相對原子質(zhì)量和名稱。

      解:設(shè)此元素為M,則硫化物的化學(xué)式為MS2,氯化物化學(xué)式為MCl4,由已知條件知:MS2∶MCl4=100∶202

      (M+64)∶(M+142)=100∶202(M+142)×100=(M+64)×202 M=12.47

      答:此元素的相對原子質(zhì)量是12.47,是碳元素。

      例2: x和y兩元素組成的A和B兩化合物,A的分子組成為xy2,其中x的質(zhì)量分?jǐn)?shù)為44.1%,B分子中x的質(zhì)量分?jǐn)?shù)為34.5%,B的化學(xué)式為

      [

      B

      ]

      A.x2y

      B.xy3

      C.xy

      D.x3y 例3:一包氯化銨(NH4Cl)化肥中,混入了少量某種其它化肥,此包氯化銨化肥中的含氮量為27.5%,則入的化肥可能是

      (A)A、CO(NH2)2

      B、(NH4)2SO4

      C、NH4HCO3

      D、KNO3 例

      4、當(dāng)氨肥硝酸銨[NH4NO3]和尿素[CO(NH2)2]所含氮元素質(zhì)量相同時,它們的質(zhì)量比是A、1∶1

      B、8∶3

      C、4∶3

      D、2∶3

      (C)例

      5、R、X兩元素形成多種化合物在RX中R元素的質(zhì)量分?jǐn)?shù)為49.7%,則下列化合物中R元素質(zhì)量分?jǐn)?shù)大于43%的是

      ()

      (A)RX

      2(B)R2X

      3(C)R2X

      (D)R2X5 【練習(xí)】

      1、已知n個銀原子的質(zhì)量為mkg,a個碳原子(測定相對原子質(zhì)量的一種碳原子)的質(zhì)量為bkg,則銀原子的相對原子質(zhì)量可表示為

      [ A

      ]

      學(xué)智教育

      A.12am/bn

      B.a(chǎn)m/12bn

      C.12bn/am

      D.bn/12am

      2、已知K2MnO4的式量為m,若鉀的相對原子質(zhì)量為a,氧的相對原子質(zhì)量為b,則錳的相對原子質(zhì)量(表達式)為x=m-2a-4b。

      3、某元素R的氧化物化學(xué)式為R2O3,若R與氧氣化合時的質(zhì)量比為9∶8,則R元素的相對原子質(zhì)量為

      [ C

      ] A.9

      B.13

      C.27

      D.56

      4、某物質(zhì)的化學(xué)式是RH4,其中含氫25%,則R元素的相對原子質(zhì)量為______。

      5、由C2H6和C2H60組成的混合物中,氧元素的質(zhì)量分?jǐn)?shù)為A%,則碳元素的質(zhì)量分?jǐn)?shù)為。21

      學(xué)智教育

      第1節(jié)

      大氣層

      教學(xué)目標(biāo)

      1、了解大氣層的重要性。

      2、了解大氣溫度的垂直分布特點。

      3、掌握大氣的垂直分布規(guī)律。

      4、理解對流層的特點,探究對流的形成。

      重點難點分析

      重點:大氣的垂直分層規(guī)律

      難點:對流層的特點;探究對流的形成教、學(xué) 預(yù) 設(shè)

      一、大氣的重要性

      地球周圍被一層很厚的空氣包圍著,它一直延伸到3000千米的高空(主要集中在1000千米的高度)。包圍地球的空氣層叫大氣層,空氣也叫大氣。

      【補充】大氣的成分:由氮氣、氧氣、二氧化碳、稀有氣體、臭氧、水蒸氣以及懸浮在其中的固體雜質(zhì)等物質(zhì)組成。

      【討論】如果沒有大氣,地球會變得怎樣?

      提示:地球?qū)⒆兊煤驮铝帘砻嬉粯樱瑳]有天氣變化,沒有聲音,易受隕石的侵襲,溫度較差增大等。

      大氣作用:

      1、保護地球,如避免流星的襲擊

      2、大氣中的各種氣體,都是人類不可缺少的資源(舉例:氧氣進行生命活動必需的;二氧化碳是光合作用的重要原料)

      3、臭氧層能保護地面上的生物免受太陽紫外線的傷害

      4、水蒸氣能成云致雨

      二、大氣的溫度

      【讀圖】大氣溫度的垂直分布圖

      特點:

      1、大氣溫度的變化范圍約在-84℃--2500℃之間。

      學(xué)智教育

      2、在85千米以上,大氣的溫度呈逐漸上升趨勢(想一想為什么?太陽輻射強)。

      3、在0-12千米、55-85千米之間氣溫隨高度的增加而降低

      4、在12-55千米之間,氣溫隨著高度的增加溫度升高。【思考】哈勃望遠鏡的外面為什么要穿一件銀白色的“外衣”?

      ——高層大氣溫度高、太陽輻射強,銀白色的金屬外殼可以反射熱的輻射,避免高溫下外殼熔化。

      三、大氣的分層

      根據(jù)大氣的溫度、密度和物質(zhì)組成等特點(大氣溫度在垂直方向上的變化是我們對大氣進行分層的主要依據(jù)。),把地球大氣層分為五層,即對流層(0-17千米)平流層(17-50千米)中間層(50-80千米)暖層(80-500千米)

      外層(500千米以上)外層就是地球大氣與宇宙間的過渡層。1000千米以上,大氣變得十分稀薄,密度很小。5000千米以外,大氣已接近真空。

      四、對流層的特點

      1、對流層是大氣的底層。

      2、在兩極和赤道地地區(qū)的厚度不同。兩極厚度約8千米,在赤道增大到17-18千米。

      3、對流層集中了地球四分之三的大氣質(zhì)量和幾乎全部的水汽、固體雜質(zhì)。

      4、對流層最顯著的特點有強烈的對流運動?!咎骄繉嶒灐繉α魇窃鯓有纬傻膶嶒?/p>

      1.燒杯中加高錳酸鉀或直接用對流實驗裝置。2.

      燃香的實驗用實驗室的現(xiàn)成器材,現(xiàn)象非常明顯。結(jié)論:受熱處空氣上升,兩側(cè)溫度低的地方空氣下沉。

      【小結(jié)】想一想對流層的溫度特點,對形成對流有利嗎?――它的溫度特點是氣溫隨高度的增加而降低,有利于對流的形成。

      學(xué)智教育

      所以,顯著的對流運動和充足的水汽,使對流層的天氣現(xiàn)象復(fù)雜多變,云、雨、雪、和雷電等主要的天氣現(xiàn)象都發(fā)生在這一層。對流層的各種天氣變化影響著生物的生存和行為,對流層是大氣層中與人們生活和生產(chǎn)關(guān)系最密切的一層。

      【拓寬】冷空調(diào)應(yīng)該怎樣裝?冷藏室的冷凝管為什么要安裝在室的上部?――形成對流,達到制冷效果。

      學(xué)智教育

      第2節(jié)

      天氣和氣溫

      教學(xué)目標(biāo)

      1、理解天氣的概念

      2、知道什么是氣溫,以及測量和度量氣溫的常用儀器和方法。

      3、學(xué)會測量氣溫

      4、了解氣溫與人們的生活和其它生物的關(guān)系 重點難點分析

      重點:氣溫的觀測

      難點:探究為什么氣象觀測中溫度計要放在百葉箱里 教、學(xué) 預(yù) 設(shè) 一. 天氣是什么

      短時間內(nèi)近地面的大氣溫度、濕度、氣壓等要素的綜合狀況稱為天氣。刮風(fēng)、下雨、雷電等都是天氣現(xiàn)象?!咀x圖】2-

      6、2-7感受天氣

      天氣是由許多要素組成的,其中主要的是氣溫、氣壓、風(fēng)、濕度和降水?!居懻擃}】

      1、判別描述天氣與氣候的詞語

      2、說說當(dāng)天的天氣狀況

      二、氣溫

      1、氣溫的含義:空氣的溫度叫氣溫。描述當(dāng)?shù)乜諝獾睦錈岢潭?。氣溫是?gòu)成天氣的基本要素。

      2、測量氣溫的工具:溫度計

      【分類】水銀溫度計、酒精溫度計、金屬溫度計等;普通溫度計、最高溫度計、最低溫度計 【復(fù)習(xí)】溫度計的結(jié)構(gòu)和制造原理

      3、氣溫度量單位:攝氏度(℃)【設(shè)問】一般把溫度計放在一個漆成白色的百葉箱里,為什么? 【探究實驗1】用溫度計分別測量百葉箱內(nèi)和百葉箱外的氣溫

      學(xué)智教育

      時間

      上午

      中午

      下午

      晚上

      溫度(百葉箱內(nèi))溫度(百葉箱外)

      據(jù)表中的數(shù)據(jù),進行分析,得出實驗結(jié)論: 1)百葉箱內(nèi)的氣溫比箱外低;

      2)百葉箱內(nèi)的溫度波動比較小,所以更能反映真實的氣溫。【探究實驗2】探究一天中氣溫最高值和最低值大概出現(xiàn)在什么時間

      實驗結(jié)論:一般氣溫的最高值出現(xiàn)在午后2時,氣溫的最低值出現(xiàn)在日出前后?!鞠胍幌搿窟@是為什么?與太陽輻射和大地散熱有關(guān)

      4、氣溫與人類生活和其它生物的關(guān)系――非常密切

      【舉例】

      1、人類的生產(chǎn)方面:春播、夏收;冬季作物的防凍;農(nóng)作物有各自最適宜的生長溫度;

      2、人類的生活方面:空調(diào)、暖氣;避暑療養(yǎng);

      3、生物的行為:狗在高溫時的表現(xiàn);蛇的冬眠、蛙的產(chǎn)卵等。出示圖或?qū)嵨?,略作講解構(gòu)造與原理、用途等

      引導(dǎo)學(xué)生在課外用連續(xù)觀測的方法得出結(jié)論,而且晴天的觀測效果比陰天好。軼事 記錄

      最高溫度計和最低溫度計的制作原理是什么?這個問題學(xué)生提了出來,但是教師真的很難搞懂,何況學(xué)生。課后 反思

      學(xué)智教育

      限于學(xué)校的實驗條件,氣溫的觀測只能放在課后或者是要求學(xué)生自主完成。探究實驗的難度較大,學(xué)生盡管測出了溫度,但很難達到教學(xué)所要求的整理和比較能力。故而也難以得出結(jié)論。

      如果能夠補充氣候的有關(guān)知識,通過對比教學(xué),學(xué)生更易于掌握天氣的描述詞語

      課內(nèi)探究實驗,兩人一組 軼事記錄

      利用高錳酸鉀來演示對流實驗(用對流管),現(xiàn)象清晰明了。學(xué)生頗感興趣,對于分析對流的成因非常易于接受。線香的實驗也是在玻璃鐘罩內(nèi)進行,效果很好。課后反思

      通過實驗來了解對流層的特點,學(xué)生易于接受。補充大氣的作用,使學(xué)生對大氣與生活的關(guān)系更了解。對于飛機和衛(wèi)星在大氣中的分布學(xué)生很難理解。其實,包括老師也能以理解。

      學(xué)智教育

      第3節(jié)

      大氣的壓強教

      教學(xué)目標(biāo)

      1.能列舉證明大氣壓存在的實驗現(xiàn)象,并能用大氣壓解釋有關(guān)現(xiàn)象。

      2. 能說出標(biāo)準(zhǔn)大氣壓的數(shù)值,說出測量大氣壓的工具:水銀壓強計和空盒壓強計。3. 3.能說出氣體和液體的流速與壓之間的關(guān)系:流速越大,壓強越小。并能用這一關(guān)系解釋有關(guān)現(xiàn)象。

      重點難點分析 重點:

      1、氣壓的觀測

      2、大氣壓存在的證明

      3、氣體和液體的流速與壓強的關(guān)系 難點:

      1、大氣壓的大小

      2、氣體和液體的流速與壓強的關(guān)系 教 學(xué) 預(yù) 設(shè)調(diào) 控 對 策

      一、大氣壓的存在 【實驗引入】

      1、器材:一杯水(染成紅色),一個空杯,一個膠頭(或橡皮套),一根玻璃管(兩端開口,粗細均勻,長20cm,內(nèi)徑約5~10mm均可)

      2、演示過程

      1).出示玻璃管,將空杯置于管的正下方,然后向管內(nèi)倒水,可看到水從管底流出。2).左手拿管,并且用食指緊緊堵住玻璃管的下端,仍然向管內(nèi)注入水,至滿。3).教師提問:為什么水不會從下面流出?

      學(xué)生微笑,齊答:因為管底被手指堵住了。筆者肯定學(xué)生的回答,并指出:由于管底被手指堵住,所以手指對管內(nèi)的水產(chǎn)生向上的壓強,支承住了水柱。接著置疑:若此時將管倒拿,使其開口端朝下,水會不會流出?學(xué)生紛紛猜測,形成懸念。

      4).左手拿管不變,同時用右手中指抵住玻璃管的上口,然后將管倒置,(倒置過程中,手指不要松開)。

      學(xué)智教育

      5).接著故意緩慢移開右手指,使下面的管口露出。這時可見紅色水柱并沒有流出來!

      學(xué)生大吃一驚!教師自言自語:咦,為什么水沒有流出來呢?(可用左手倒拿著管,夸張地放到眼底瞧一瞧)難道管里的水突然沒有了重力嗎?難道是老師會氣功,‘發(fā)功’將管內(nèi)的水吸住了嗎?

      學(xué)生輕笑,同時產(chǎn)生了想獲知正確答案的強烈欲望。

      6).啟發(fā):雖然我們看不見管口有物堵住它,但管口附近是不是任何物體都沒有呢? 學(xué)生茅塞頓開――有空氣存在。因勢利導(dǎo):在管口四周存在著我們看不見的大量空氣,這些氣體起到了手指的作用,堵住了管口,使管內(nèi)的水竟然無可奈何地呆在里面。這說明了這些大氣對管底的水面有向上的壓強,支承著水柱。

      7).這時,仍有學(xué)生半信半疑,可進一步說明:因為現(xiàn)在管內(nèi)的水只有下面受到了大氣壓強的支承作用,所以很難流出;但如果同時有大氣作用在管的上水面,那么上、下作用的氣壓相互抵消,水就會在重力作用下流出來。

      8).松開左手食指,水應(yīng)聲落下。(學(xué)生開始相信大氣有壓強)

      9).改用膠頭,套住玻璃管的一端,再做一遍,同樣獲得滿意效果?!髿鈮簭姶_實存在.液體在各個方向上存在壓強,氣體是否也一樣呢?

      【學(xué)生實驗】探究大氣壓強是否向各個方向都有.

      ①向上.玻璃杯裝滿水用紙片擋住,倒立玻璃杯,紙片不脫落,如圖1.說明向上有大氣壓. ②向下.將剝了殼的熟雞蛋塞住剛燒過酒精棉球的廣口瓶口,很快雞蛋就被壓進廣口瓶中.說明向下有大氣壓.

      ③猜想向左、向往是否也有大氣壓,如何證實?(讓學(xué)生自己證實)

      通過上述演示實驗及日常生活經(jīng)驗得知——在氣體內(nèi)部向各個方向都有壓強. 【解釋】圖2-

      14、2-

      15、2-16(學(xué)生動手實驗體會吸盤的作用)倘若沒有大氣壓強作用在液體的表面,各種液體就不可能被抽吸起來。從這個含義上講,一切抽吸液體的過程,其實都是大氣壓強將液體“壓”上來的過程.【演示實驗】抽出可樂瓶中的氣體

      學(xué)智教育

      實驗現(xiàn)象:可樂瓶變癟 實驗結(jié)論:氣體向各個方向上都有壓強

      【設(shè)問】大氣壓確實是存在的,而且各個方向上都有壓強。那么大氣壓究竟有多大呢? 【演示】馬德堡半球?qū)嶒?/p>

      實驗現(xiàn)象:兩個半球需用很大的力才能拉開 提出疑問:是什么力使兩個半球合得那么攏?

      討論后得出:是大氣的壓力把兩個半球緊緊壓在一起的,進而讓學(xué)生確信大氣壓的存在.因為地球周圍的大氣受到地球的吸引,即大氣也受到重力的作用,所以大氣對浸在其內(nèi)的物體就有壓力、壓強。如果半球內(nèi)為真空,那么要拉開半球需要的力約為7065牛。――馬德堡半球?qū)嶒炞C明了大氣壓的存在,而且說明大氣壓是很大的?!鹃喿x】人體中的“馬德堡半球”

      二、大氣壓的大小

      大氣壓的大小跟我們的生活密切相關(guān),我們應(yīng)該知道大氣壓的測量方法。

      1、大氣壓的大小可以用空盒氣壓計或水銀氣壓計進行測量。

      【出示】空盒壓強計(或叫金屬盒壓強計、無液壓強計)觀察:其上有兩行刻度,一行以百帕為單位,一行以毫米汞柱為單位。說明它的原理和構(gòu)造?!境鍪尽克y壓強計

      補充實驗:托里拆利實驗――進行簡單的實驗說明、數(shù)據(jù)讀數(shù)和分析,大氣壓支持著玻璃管中的水銀柱。當(dāng)大氣壓發(fā)生變化的時候,水銀柱的高度會發(fā)生變化。從中說明水銀壓強計的原理。

      【簡單比較】:兩種壓強計的優(yōu)缺點

      2、大氣壓的變化:

      1)大氣壓的大小與大氣的密度有關(guān)--解釋:大氣壓的產(chǎn)生是由于大氣有重力。2)大氣壓的大小隨著高度的增加而減小--解釋:大氣的密度隨著高度而減小。

      實例:高山上氣壓很低。有些登山運動員在進入高山地區(qū)后,會發(fā)生高山病。高山病的癥狀

      學(xué)智教育

      差別很大,包括:頭暈、頭痛、耳鳴、惡心、嘔吐、脈搏和呼吸加速、四肢麻木等。每個人的反應(yīng)隨一系列的條件而不同,主要決定于訓(xùn)練的程度和海拔高度的轉(zhuǎn)變速度等。登山運動員初次迅速攀登很高的山峰時,會出現(xiàn)以下現(xiàn)象:睡眠不好,全身感覺不舒服,軟弱無力,懶散和情緒低落,動作協(xié)調(diào)性差。呼吸系統(tǒng)的癥狀是:氣喘,時常感到空氣不足,睡眠時發(fā)生周期性的呼吸停頓,夜間感到窒息發(fā)悶。由于心臟血管系統(tǒng)機能狀況變化引起頭暈、鼻出血、耳鳴和血管跳動的感覺,皮膚和粘膜變得青紫或蒼白,常常惡心和嘔吐。嚴(yán)重的會陷入昏迷、甚至死亡。

      高山病的主要原因是高山地區(qū)空氣稀薄,大氣壓低,人們呼吸時吸入的氧氣的分壓也低,造成肺泡中的氧分壓降低,血液中含氧量減少。

      平原地區(qū)的青年人在高山地區(qū)居住一段時間后,對高山氣候的適應(yīng)能力和缺氧的抵抗能力都會提高。一般地說,高山病的急性癥狀就會逐漸減輕,以至消失。身體健康的人和訓(xùn)練有素的登山運動員對高山氣候的適應(yīng)能力也強。

      3)在海平面附近,大氣壓的數(shù)值接近1.01×105帕(760毫米汞

      柱)規(guī)定:這個大氣壓值稱為標(biāo)準(zhǔn)大氣壓。

      【討論】要求簡單地運用液體壓強公式進行計算。并與磚的壓強進行比較?!締栴}】這么大的壓強,我們?yōu)槭裁礇]有受壓的感覺? --解釋:人對環(huán)境的適應(yīng),人的體內(nèi)也有壓強,它抗衡著體外的大氣壓。軼事記錄

      本節(jié)課的引入很有意思,學(xué)生真的被深深地吸引。雖然這種現(xiàn)象在生活中出現(xiàn),但往往平時沒有注意。通過教師的渲染,學(xué)生更能體會到科學(xué)就在身邊。只不過是平時習(xí)以為常罷了。課后反思

      本節(jié)內(nèi)容分3課時。第一課時主要為大氣壓的存在,補充一些實驗;第二課時主要講大氣壓的大小測定,補充托里拆利實驗。第三課時:流速與壓強的關(guān)系。具體見后面的教案。

      學(xué)智教育

      第3節(jié)

      大氣的壓強(第3課時)教學(xué)目標(biāo)

      1、知識與技能:能說出氣體和液體的流速與壓之間的關(guān)系:流速越大,壓強越小。并能用這一關(guān)系解釋有關(guān)現(xiàn)象

      2、過程與方法:通過觀察與實驗,認(rèn)識氣體的壓強跟流速有關(guān)的現(xiàn)象。

      3、情感、態(tài)度與價值觀:初步領(lǐng)略氣體壓強差異所產(chǎn)生現(xiàn)象的奧妙,獲得對科學(xué)的熱愛、親近感。

      重點難點分析

      重點:氣體和液體的流速與壓強的關(guān)系

      難點:用氣體和液體的流速與壓強的關(guān)系解釋有關(guān)現(xiàn)象 教 學(xué) 預(yù) 設(shè)調(diào) 控 對 策

      【圖片引入】就你看到的這幅圖片,你能提出一些問題來嗎?老師有一個問題:在火車的站臺上,標(biāo)有一道平行于鐵軌的直線。當(dāng)列車駛過時,不允許旅客站在這條線內(nèi),以保證人體與鐵軌離開足夠的距離。你知道這是為什么嗎? 要解釋這個問題,就讓我們一起來做幾個探究實驗吧!【實驗】研究氣流的流速與壓強的關(guān)系

      1)找一條薄紙帶,捏住紙的一端,讓紙自然下垂,當(dāng)你用嘴朝水平方向吹氣時,你會發(fā)現(xiàn)什么現(xiàn)象?若改變吹氣的力量和速度,紙帶會發(fā)生什么變化? 現(xiàn)象:紙向上飄起

      2)找兩張相同的薄紙,用手捏住兩張紙的一端,讓兩張紙自然下垂,相距3-5厘米,并使兩張紙保持平行。沿兩張紙的中間向下吹氣時,猜測會出現(xiàn)的現(xiàn)象。試一試,結(jié)果與你的猜測相同嗎?

      學(xué)生猜測:紙條會被氣流向兩邊吹開 現(xiàn)象:當(dāng)吹氣時,兩紙條反而向中間合攏 分析:吹氣時紙條為什么會向中間合攏呢?

      肯定是紙條受到了力的作用,而且力的方向是指向內(nèi)側(cè)。那么是什么物體施與紙條力的作用

      學(xué)智教育

      呢?我們分析一下:與紙條接觸的只有空氣。吹氣前,兩條紙互相平行,保持一定的間距,沒有吸引和推斥,表明它們受到外側(cè)和內(nèi)側(cè)的力互相平衡;吹氣時,兩條紙相互靠近。紙條外側(cè)的氣體壓強沒有發(fā)生變化,說明是紙條內(nèi)側(cè)的氣體壓強變小了。吹氣時與不吹氣時有什么不同嗎?兩紙條內(nèi)側(cè)的氣體的流速較大。

      可見,氣體流速的改變,改變了氣體的壓強;而且是氣體的流速越大,壓強越小。【教師】現(xiàn)在你能解釋在火車站的站臺上,人為什么要與行駛的列車保持適當(dāng)距離了嗎? 行駛的火車和人之間的氣流速度大,壓強變小。人外側(cè)的大氣壓大于火車和人之間的氣壓。這種情況下,會使人大氣壓擠到火車前,這樣非常危險。

      【實驗】把一支玻璃管插入水中,當(dāng)用另一支玻璃管對著它的上端吹氣時,有什么現(xiàn)象?試一試,怎樣對此現(xiàn)象作出解釋。現(xiàn)象:有水從管口吹出。

      解釋:玻璃管的上端氣流速度大,壓強?。ㄐ∮诖髿鈮海?。所以玻璃管中的水在大氣壓的作用下從管口出來。

      【教師】跟氣體一樣,液體的壓強也會隨著流速的增大而減小。

      講述:在1912年秋季的一天,當(dāng)時世界上最大的遠洋輪之一“奧林匹克號”正在大海上航行,離它100米左右的地方,有一艘比它小得多的鐵甲巡洋艦“豪克號”與它平行疾駛。突然,小軍艦偏離了航道,一個勁地向“奧林匹克號”沖去,結(jié)果與“奧林匹克號”相撞。大家肯定知道原因了。首先大家要明白:水流動而船不動與船運動而水不動效果時相同的,即運動是相對的(畫圖說明)。

      當(dāng)兩船彼此接近平行行駛時,兩船之間的水由于被擠在一起,流速要比外部大一些,壓強就要比外部小一些。這樣,水流的壓力差將使兩船相互“吸引”,外部壓強較大的水就把兩船擠在一起而發(fā)生碰撞事故。

      因此,同方向高速平行行駛的船舶要保持一定的距離。

      【教師】氣體和液體一樣,受到外界環(huán)境影響時都會流動,并且流動的規(guī)律也相同,因此人們將液體和氣體統(tǒng)稱為流體。關(guān)于流體有兩個著名的定理:連續(xù)性定理和伯努利定理。伯努利定理:流體在一個管道中流動時,流速大的地方壓力小,流速小的地方壓力大。

      學(xué)智教育

      流體的連續(xù)性定理:當(dāng)流體連續(xù)不斷而穩(wěn)定地流過一個粗細不等的管道時,由于管道中任何一部分的流體都不能中斷或擠壓起來,因此在同一時間內(nèi),流進任一切面的流體的質(zhì)量和從另一切面流出的流體質(zhì)量是相等的。

      【教師】當(dāng)我們了解了伯努利定理后,我們可以深入了解飛機的飛行原理。我們發(fā)現(xiàn)機翼的翼型不是平的,而是平凸型的。(圖示)【實驗】紙飛機機翼上升實驗

      我們發(fā)現(xiàn):空氣流到機翼前緣后,分成上下兩股氣流,分別沿機翼的上下表面流過,在機翼后緣又重新匯合向后流去。機翼的上表面凸起,使流速加快,壓強減??;而機翼的下表面流速小,壓強增大。于是在機翼的上下表面出現(xiàn)了壓強差,就有了壓力差,這成為飛機上升的動力。當(dāng)升力大于飛機重力的時候,飛機就可以升空了?!狙a充】實驗并解釋現(xiàn)象

      1、吹蠟燭

      2、吹不下來的乒乓球)

      3、懸空的豌豆(先教師演示懸空的乒乓球)【分析題】:

      1、用細線吊起一個空的塑料瓶,用手轉(zhuǎn)動飲料瓶,使它繞對稱軸線旋轉(zhuǎn)。轉(zhuǎn)動的塑料瓶帶動四周的空氣繞它旋轉(zhuǎn)。如果這時用電

      風(fēng)扇向它吹風(fēng),由于瓶的轉(zhuǎn)動,它兩側(cè)的風(fēng)速將不一樣。按照氣流和壓強的關(guān)系,旋轉(zhuǎn)著的飲料瓶應(yīng)當(dāng)向哪個分析移動?

      2、乒乓球前進中由于不同的旋轉(zhuǎn)方向會沿不同的徑跡運動,且乒乓球旋轉(zhuǎn)時會帶動周圍空氣的旋轉(zhuǎn)。運動員用三種不同的擊球方法把乒乓球擊出,請判斷,圖中1、2、3三條徑跡哪一條是上旋球(球沿逆時針方向旋轉(zhuǎn)),哪一條是下旋球(球沿順時針方向旋轉(zhuǎn)),哪一條是不旋球。試說明為什么上旋球應(yīng)該沿著你所選的徑跡運動?!拘〗Y(jié)】流速與壓強的關(guān)系 軼事記錄 課后反思

      學(xué)智教育

      本節(jié)課為公開課。注重實驗和探究,把一些實驗通過各種方式聯(lián)系起來,有屬于探究的,有屬于驗證的,也有屬于趣味的和綜合的。

      學(xué)智教育

      第4節(jié)

      大氣壓與人類生活

      教學(xué)目標(biāo)

      1、了解大氣壓對天氣的影響,能說出晴朗的天氣氣壓較高,陰雨的天氣氣壓較低。

      2、了解大氣壓對人體的影響,氣壓變化過大會使人產(chǎn)生不良的反應(yīng)。

      3、了解液體的沸點與壓強的關(guān)系:當(dāng)氣壓增大時,液體的沸點升高;當(dāng)氣壓減小時,液體的沸點降低。并會用這一結(jié)論來解釋有關(guān)現(xiàn)象和解決簡單的實際問題。

      4、了解大氣壓在真空保存袋、吸塵器等生活用具中所起的作用。通過探究吸塵器內(nèi)部結(jié)構(gòu)的過程,學(xué)習(xí)黑箱問題的解決方法。重點難點分析

      重點:氣壓對天氣的影響 難點:探究吸塵器內(nèi)部結(jié)構(gòu) 課程資源的準(zhǔn)備與開發(fā) 實驗、實物展示

      教、學(xué) 預(yù) 設(shè)調(diào) 控 對 策

      一、大氣壓對天氣的影響

      1、大氣壓的特點:

      1)、大氣壓隨高度的增大而減小

      2)、同一高度的不同區(qū)域,大氣壓的數(shù)值也不一定相同 3)、同一地點的不同時間,大氣壓也會不同

      2、大氣壓對天氣的影響:

      高氣壓多晴朗天氣,低氣壓區(qū)多陰雨天氣。(畫圖說明)

      二、大氣壓對人體的影響 大氣壓對人體有一定的影響:

      1、人的情緒、心情受氣壓影響較大

      2、人對氣壓的變化有逐步適應(yīng)的過程(高山病的說明)

      3、減壓實驗說明:人體內(nèi)也有壓強。當(dāng)體內(nèi)外壓強失去平衡后,也會對人體產(chǎn)生不良的影響。

      學(xué)智教育

      【討論】我們的周圍的大氣壓大約有105帕,這么大的氣壓作用在我們身上,我們?yōu)槭裁礇]有感覺?

      --猜測原因:可能時我們已經(jīng)適應(yīng)了,也可能時我們的體內(nèi)也有壓強,它跟體外的大氣壓相平衡。

      【閱讀】宇航員為什么要穿上宇航服?

      三、氣壓對液體沸點的影響:

      【提出問題】為什么高山上用普通的鍋難以將飯煮熟? 【實驗】研究液體的沸點和氣壓的關(guān)系 【現(xiàn)象】增大氣壓時原來沸騰的水不再沸騰 減小氣壓時原來不在沸騰的水又重新沸騰

      【結(jié)論】液體的沸點與氣壓有關(guān):當(dāng)氣壓增大時,液體的沸點升高;當(dāng)氣壓減小時,液體的沸點會降低。

      【練習(xí)】用該知識點解釋現(xiàn)象:

      1、高壓鍋煮飯的原理

      2、低壓鍋的原理

      四、生活用品與大氣壓

      1、真空壓縮保存袋;

      2、吸塵器吸塵器是怎樣工作的 【為什么做】

      吸塵器是利用大氣壓工作的一種清潔工具。你可能使用過它:當(dāng)吸塵器接上電源工作時,外面帶著塵垢的空氣會從地刷的入口進入吸塵器,而凈化的空氣則從吸塵器的尾部排出。可是你知道吸塵器的內(nèi)部結(jié)構(gòu)和工作原理嗎?恐怕很多同學(xué)和你一樣不了解。那么就讓我們帶著這個任務(wù)來進行下面的探究活動吧!【怎樣做】

      首先讓我們提出問題:吸塵器要達到吸塵的目的,內(nèi)部應(yīng)有什么結(jié)構(gòu)?說說各個器件在吸塵器中的作用。(要起塵,應(yīng)該有地面刷;要吸塵,必須使地面刷前端的空氣能進入吸塵器,這

      學(xué)智教育

      就需要有風(fēng)機使吸塵器中的空氣高速排出;濾塵,則需要濾塵器(袋))。

      那么,在吸塵器的工作過程中,大氣壓的作用又表現(xiàn)在哪里?(其實吸塵器靠電動機高速驅(qū)動風(fēng)機葉輪旋轉(zhuǎn),使空氣高速排出,而風(fēng)機前端吸塵部分的空氣不斷地補充風(fēng)機中的空氣,致使吸塵器內(nèi)部產(chǎn)生瞬時真空,和外界大氣壓形成負壓差。在此壓差的作用下,吸入含灰塵的空氣,經(jīng)濾塵器過濾,排出清凈的空氣,負壓差越大風(fēng)量越大,則吸塵能力也越大。)接著根據(jù)你和同學(xué)的生活經(jīng)驗和知識經(jīng)驗,你認(rèn)為各個器件應(yīng)該怎樣連接呢?如長接管與地面刷、彎管、軟管與吸塵器、吸塵器內(nèi)部器件的連接等。

      最后,與其他小組交流,看看誰的描述更合理;并與老師出示的吸塵器內(nèi)部結(jié)構(gòu)實物或圖,看看你的描述與實際情形是否相接近? 【學(xué)到了什么】

      通過在教師指導(dǎo)下的探究活動,你能夠體會到科學(xué)知識在生活實際中的應(yīng)用――吸塵器就是利用大氣壓來工作的。

      你一定對你在探究中出現(xiàn)的偏差有了更深的認(rèn)識,體驗到了探索科學(xué)的道路是不平坦的。通過這樣的探究活動也培養(yǎng)了我們探索科學(xué)的精神、科學(xué)素養(yǎng)、信息素養(yǎng)、技術(shù)素養(yǎng)。我們從問題的提出、證據(jù)的收集、方案的制訂和實施到解釋的形成,檢驗和結(jié)論的得出等等都是我們的自主發(fā)現(xiàn)?!具M一步的研究】

      知道了吸塵器的內(nèi)部結(jié)構(gòu)和工作原理,你肯定很想知道使用吸塵器應(yīng)該注意什么。下面就是有關(guān)吸塵器的使用及保養(yǎng)的小竅門,供你參考。

      1、吸塵器工作時應(yīng)避免開關(guān)頻繁啟動以免啟動電流沖擊過大,燒壞電器設(shè)備。

      2、注意墻壁電源及電源接線板插接牢固,以防止非人為因素電源開關(guān)的瀕繁啟動。

      3、桶外軟管部分及按口部分,應(yīng)避免用力拉撞,防止這些部件損壞。

      4、因吸塵器的輪子為萬向輪,其運動方向有隨意性,固在工作中拉動吸塵器時,應(yīng)防止撞壞其他物品及自身輪子。

      5、吸塵器的過濾網(wǎng)罩應(yīng)及時清洗以防灰塵雜物過多堵死過濾網(wǎng),增大電機工作負荷。

      6、工作中,應(yīng)將地毯上的較大雜物預(yù)先清理,以防止牙簽、發(fā)卡、圖釘?shù)瓤ㄗ≤浌芗捌?/p>

      學(xué)智教育

      他部位。

      7、為使集塵箱內(nèi)干凈、整潔,建議使用吸塵袋(須另配)。

      8、使用完畢后,應(yīng)將吸塵器及塵桶內(nèi)外、軟管、扒頭、電線擦拭干凈以備下次使用。

      9、吸塵器如無特殊吸水功能,嚴(yán)禁用于吸水處理。

      10、除塵刷上刷毛如磨損嚴(yán)重,應(yīng)及時更換。吸塵器的電機軸承,應(yīng)定期加潤滑油。吸塵器電機的炭刷,長期使用后如產(chǎn)生磨損,應(yīng)更換新炭刷。吸塵器內(nèi)的密封膠墊若老化,應(yīng)更換新膠墊。

      11、如遇緊急情況出現(xiàn)故障時應(yīng)馬上停機,通報有關(guān)部門管理人員,找廠家及經(jīng)銷商專業(yè)維修人員進行維修。

      3、離心式水泵、活塞式抽水機(用圖分析)利用大氣壓工作

      說明為什么在啟動機器前要先灌滿水以及工作的主要過程。軼事記錄

      實驗很成功。充分說明知識的呈現(xiàn)可以通過實驗探究來實現(xiàn)。課后反思

      本節(jié)課能聯(lián)系實際,學(xué)生較容易理解和掌握。學(xué)生對這塊內(nèi)容

      學(xué)智教育

      第5節(jié)

      風(fēng)

      教學(xué)目標(biāo)

      1、了解風(fēng)是怎樣形成的

      2、知道風(fēng)向、風(fēng)速的表示方法和度量單位

      3、學(xué)會用風(fēng)向標(biāo)、風(fēng)速儀測定風(fēng)向和風(fēng)速的方法

      4、了解風(fēng)對人類活動和動物行為的影響 重點難點分析 重點:風(fēng)的觀測

      難點:風(fēng)的形成;目測風(fēng)向、風(fēng)速 課程資源的準(zhǔn)備與開發(fā)

      風(fēng)速儀和風(fēng)向標(biāo),并實地測試風(fēng)向和風(fēng)速

      教、學(xué) 預(yù) 設(shè)調(diào) 控 對 策

      【演示并思考】把充滿氣體的氣球充氣口松開,會感到氣球內(nèi)的空氣一涌而出,這是為什么?

      一、風(fēng)

      1、風(fēng)是空氣的水平運動。風(fēng)是從高氣壓區(qū)流向低氣壓區(qū)的。

      2、風(fēng)的兩個基本要素:風(fēng)向和風(fēng)速 1)風(fēng)向是紙風(fēng)吹來的方向。天氣觀測和預(yù)報中常使用8種風(fēng)向。表示方法:用一短線段表示。用紙飛機測風(fēng)向 【為什么做】

      風(fēng)向和風(fēng)速是測量風(fēng)的兩個基本要素。觀測風(fēng)向的儀器叫風(fēng)向標(biāo),由箭頭、水平桿和尾翼三部分組成。那么風(fēng)向標(biāo)是怎樣指示風(fēng)向的呢?風(fēng)向是由風(fēng)向標(biāo)箭頭的方向來指示,還是由箭

      學(xué)智教育

      尾的方向來指示呢?風(fēng)向又是怎么規(guī)定的呢?就讓我們用紙飛機測風(fēng)向這個簡單的模擬實驗來解決吧!【怎樣做】

      折一紙飛機,中間用鉛筆穿過(要讓紙飛機能在鉛筆上輕松轉(zhuǎn)動)。用手握住鉛筆,將紙飛機放在開啟的電風(fēng)扇前,觀察紙飛機的機頭和尾翼的指向。注意:此時人要站在紙飛機的后方。并借助指南針判斷風(fēng)向。【學(xué)到了什么】

      通過實驗,使我們對風(fēng)和風(fēng)向有了一個直觀的認(rèn)識:紙飛機的箭頭指向風(fēng)來自的方向。同理,在氣象觀測中,風(fēng)向是由風(fēng)向標(biāo)的箭頭指向的。

      同時也使我們明白:實驗可以使我們更簡潔明了地了解事物,也培養(yǎng)了我們的觀察能力。

      【進一步的研究】

      (1)用紙飛機測風(fēng)向的實驗使你明白了風(fēng)向標(biāo)指示風(fēng)向的事實。你是否在想:這是運用了什么原理呢?為什么風(fēng)向標(biāo)會有一定的指向呢?下面的文字,會幫助你有一個了解。風(fēng)向標(biāo)是一種應(yīng)用最廣泛的測量風(fēng)向儀器的主要部件。在風(fēng)的作用下,尾翼產(chǎn)生旋轉(zhuǎn)力矩使風(fēng)向標(biāo)轉(zhuǎn)動,并不斷調(diào)整指向桿指示風(fēng)向。風(fēng)向標(biāo)感應(yīng)的風(fēng)向必須傳遞到地面的指示儀表上,以觸點式最為簡單,風(fēng)向標(biāo)帶動觸點,接通代表風(fēng)向的燈泡或記錄筆電磁鐵,作出風(fēng)向的指示或記錄,但它的分辨只能做到一個方位(22.5°)。

      地面風(fēng)指離地平面10─12 米高的風(fēng)。風(fēng)的來向為風(fēng)向,一般用十六方位或360°表示。以360°表示時,由北起按順時針方向度量。

      (2)你知道了風(fēng)向的測量方法,一定很想知道風(fēng)速大小的測量方法。其實你也可以用簡單的模擬實驗來測量風(fēng)速。請認(rèn)真閱讀下面的文字,你就會用生活中常見的小風(fēng)車(參見三維風(fēng)車式風(fēng)速儀)或風(fēng)壓板來簡單比較風(fēng)速的大小了,動手試一試。

      2)風(fēng)速:指單位時間里空氣在水平方向上移動的距離,其單位是:米/秒、千米/時或海里/小時表示。

      測試風(fēng)速的儀器叫風(fēng)速計,它利用風(fēng)杯在風(fēng)作用下的旋轉(zhuǎn)速度來測量風(fēng)速。風(fēng)速儀有以下幾種:①風(fēng)杯風(fēng)速表②槳葉式風(fēng)速表③熱力式風(fēng)速表。

      學(xué)智教育

      風(fēng)速常用風(fēng)級表示。

      【閱讀】各風(fēng)級的名稱、風(fēng)速和目測結(jié)果

      3)風(fēng)對人類的生活有很大的影響,有些動物的行為也和風(fēng)有關(guān)?!拘〗Y(jié)】 【補充】 風(fēng)

      荷蘭利用風(fēng)能歷史悠久,自古以來就是世界聞名的“風(fēng)車之鄉(xiāng)”,這與其優(yōu)越的自然條件、不屈的民族精神和優(yōu)秀的民族智慧是分不開的。

      荷蘭位于北緯50°50′~北緯53°30′之間,在全球大氣環(huán)流所形成的風(fēng)系中,正好處于西風(fēng)帶,常年盛行西風(fēng),由于荷蘭國土的60%海拔低于1米,近40%的國土低于海平面,最高處海拔也僅300米左右,是世界上有名的“低地之國”,來自大西洋的西風(fēng)能夠長驅(qū)直入內(nèi)陸,全國風(fēng)力資源極為豐富。風(fēng)車是荷蘭人智慧的結(jié)晶。據(jù)說,世界上第一臺風(fēng)車是荷蘭人在同大自然的博斗中,于1408年發(fā)明的。到19世紀(jì)時,全國已擁有風(fēng)車18000多臺,最大的有9層樓高,風(fēng)翼長達20米,無怪乎人們叫它“風(fēng)車王國”了。

      荷蘭的風(fēng)車種類很多,從最古老的建于1450年的塔式風(fēng)車到后來的軸式風(fēng)車,都是精工制作的,顯示了荷蘭人無比的智慧和高超的工藝。荷蘭素以修筑海堤圍海造田而著稱于世。攔海造田,成為荷蘭人奮斗精神的象征,而風(fēng)車則成為荷蘭人向大海奪取土地的強有力的武器,大小風(fēng)車日夜轉(zhuǎn)動,起到了排出海水、灌溉田地的巨大作用,在荷蘭人向大海奪取土地的斗爭中立下了豐功偉績。同時風(fēng)車還被廣泛用于榨油、脫谷等生產(chǎn)勞動中,為荷蘭歷史上的繁榮與發(fā)展起到了巨大作用。

      20世紀(jì)以來,隨著電力和內(nèi)燃機的使用,傳統(tǒng)的風(fēng)車已難現(xiàn)昔日的輝煌,逐漸銷聲匿跡了,但仍有上千臺被保留下來,成為供參觀考察的景物。例如:在肯德代克,建于1740年的風(fēng)車每年吸引著20萬到30萬的參觀考察者。近年來,隨著能源危機和大量礦物能源的使用對地球環(huán)境的破壞,風(fēng)能利用重新得到人們的青睞,古老的風(fēng)

      車脫胎換骨,為荷蘭的鄉(xiāng)村和城市帶來源源不斷的電能。

      軼事記錄

      學(xué)智教育

      學(xué)生能針對幾個具體的實物--風(fēng)速儀和風(fēng)向標(biāo),提出各種各樣的問題,很值得肯定。課后反思

      這種課目的是增強學(xué)生的生活常識,所以要在激發(fā)學(xué)生學(xué)習(xí)興趣和課外知識拓展這兩個方面上下功夫。

      學(xué)智教育

      第7節(jié)

      教學(xué)目標(biāo)

      1、知道獲取天氣預(yù)報的常見方法。

      2、學(xué)會看天氣預(yù)報。

      明天的天氣會怎么樣

      3、學(xué)會看簡單的天氣圖。掌握天氣圖上重要的天氣系統(tǒng)。

      4、利用天氣圖判斷天氣狀況,并能做簡單的天氣預(yù)報。

      5、知道天氣預(yù)報信息的主要收集方法。

      6、調(diào)查當(dāng)?shù)氐奶鞖庵V語,能解釋其中的科學(xué)道理。重點難點分析

      重點:怎樣看天氣預(yù)報;

      天氣圖上的常見天氣系統(tǒng); 天氣圖和天氣形勢;

      難點:天氣圖上的等壓線和天氣系統(tǒng);

      簡單的天氣預(yù)報。教、學(xué) 預(yù) 設(shè)調(diào) 控 對 策

      【引入】根據(jù)學(xué)生預(yù)習(xí)作業(yè)交流收集當(dāng)天當(dāng)?shù)氐奶鞖忸A(yù)報的方法。

      一、獲取天氣預(yù)報的常用方法:

      ⑴通過看電視、聽廣播、撥氣象預(yù)報電話、互聯(lián)網(wǎng)上查看等獲取氣象預(yù)報信息 ⑵通過分析天氣圖,自己預(yù)測天氣 ⑶通過氣象觀測,自己制作天氣預(yù)報

      二、怎樣看天氣預(yù)報 了解天氣預(yù)報用語的含意

      ⑴“陰”指天空的總云量在8/10以上,“多云”指天空總云量在5/10到7/10,5/10到3/10為少云,3/10 以下為晴。

      ⑵12小時內(nèi)降水小于5毫米為小雨,5-15毫米為中雨,大于15毫米為大雨。降水概率表示降水的可能性大小。

      學(xué)智教育

      ⑶最低氣溫和最高氣溫的表示方法。⑷空氣質(zhì)量指數(shù)

      三、天氣圖

      --用來表示天氣形勢,是一種可以表現(xiàn)不同地方氣象信息的地圖。

      ⒈分析天氣圖時,首先要了解一些重要的術(shù)語(以圖2-47為例)

      ⑴等壓線:氣壓相等的地方的連線。根據(jù)等壓線的分布特點,可以分析出常見的天氣系統(tǒng),如高壓、冷鋒等

      ⑵鋒是影響天氣的重要天氣系統(tǒng)。冷暖空氣的交界面叫鋒面;向暖空氣一側(cè)移動的鋒叫冷鋒,常帶來降雨、大風(fēng)和降溫天氣;向冷空氣一側(cè)移動的鋒叫暖鋒,常帶來降雨天氣,氣溫升高。

      ⑶高壓、低壓、臺風(fēng)等。還要明白鋒面系統(tǒng)的移動機理,高氣壓和的氣壓系統(tǒng)的移動機理等。

      ⒉觀測天氣圖上的圖例,如暖鋒、冷鋒,還有天氣圖上的日期等。明確冷鋒、暖鋒系統(tǒng)及鋒面,同時關(guān)注等壓線上的數(shù)字來得知高壓區(qū)和低壓區(qū)。然后根據(jù)鋒面系統(tǒng)的移動方向來判斷該鋒面系統(tǒng)對所預(yù)報地區(qū)產(chǎn)生的影響,判斷該地的天氣趨勢。

      【學(xué)生練習(xí)】制作天氣預(yù)報

      學(xué)智教育

      第8節(jié)

      氣候和影響氣候的因素

      教學(xué)目標(biāo)

      ⒈了解氣候的概念及影響氣候的因素 ⒉了解緯度因素對氣候的影響

      ⒊理解比熱的概念,了解不同物質(zhì)比熱的差異 ⒋理解陸地和海洋比熱的不同對氣溫的影響 ⒌理解地形因素對氣溫和降水的影響

      ⒍了解季風(fēng)的概念,理解我國季風(fēng)的形成舉機理 重點難點分析

      重點:不同物質(zhì)的比熱;

      海洋和陸地的性質(zhì)對氣溫和降水的影響; 地形對氣溫和降水的影響; 季風(fēng)的形成

      難點:比熱的概念;

      海洋和陸地的性質(zhì)對氣溫和降水的影響;

      地形對降水的影響;

      季風(fēng)的形成

      教、學(xué) 預(yù) 設(shè)調(diào) 控 對 策

      一、氣候

      ⒈氣候的含義:氣候是指某一地區(qū)長時間內(nèi)的天氣特征,包括天氣的平均狀況和極端狀況。(與天氣的概念進行區(qū)別)

      【思考】天氣與氣候有什么不同?有什么聯(lián)系?

      ⒉我國各地氣候差異很大,是由于不同的地區(qū)影響氣候的因素不同。

      二、緯度對氣候的影響

      緯度位置不同的大地區(qū),接受太陽輻射的量不同,在地球上所處的溫度帶位置也不同。【復(fù)習(xí)】根據(jù)接受太陽輻射的多少,地球表面分成五個溫度帶。

      學(xué)智教育

      【討論】我國的緯度位置跨五帶中的哪幾帶? 【分析】海南和漠河的氣候特征

      三、海洋和陸地的性質(zhì)對氣溫和降水的影響

      【提出問題】夏天沿海地區(qū)與內(nèi)陸地區(qū)相比要涼爽得多,夏天的內(nèi)陸和沿海氣溫有較大的差異,為什么?

      【實驗】探究相同質(zhì)量的不同物質(zhì),升高相同的溫度,吸收的熱量是否相同?

      【過程】

      1、實驗器材:燒杯(質(zhì)量要盡可能相同)一對,溫度計一對,帶鐵圈、鐵夾的鐵架臺一對,酒精燈(火焰大小要一致)一對,石棉網(wǎng)一對,天平;水和煤油等。

      2、把兩個同樣的燒杯放在天平的兩盤中,分別向杯內(nèi)倒入半杯水和半杯煤油,并使天平平衡,水與煤油的質(zhì)量相等。按圖2-50所示裝配好裝置,然后用相同的酒精燈(實驗時,為了使酒精燈加熱效果相同,必須把石棉網(wǎng)調(diào)到相同的高度)加熱,使它們在相同的時間內(nèi)里吸收相同的熱量。兩杯的初溫應(yīng)該是相同的。如果不同,可用酒精燈稍加熱進行調(diào)整。

      3、經(jīng)過一段時間加熱后,觀察溫度計的示數(shù)變化,是水中還是煤油中的溫度升高得快? 【結(jié)論】

      1、實驗表明:在吸收相同的熱量時,煤油的溫度比水的溫度升高得快。也就是說,相同質(zhì)量的水和煤油升高相同的溫度時,水要多加熱一些時間,即水要吸收更多的熱量。

      2、以上的實驗反映了水與煤油這兩種物質(zhì)的不同性質(zhì)。以此延伸,就是質(zhì)量相同的不同物質(zhì),升高相同的溫度時,所吸收的熱量是不同的。

      ㈠比熱:我們把1單位質(zhì)量的某種物質(zhì),在升高1℃使所吸收的熱量,叫做這種物質(zhì)的比熱容,簡稱為比熱。

      ㈡比熱單位:焦/(千克.℃)

      讀作:焦每情千克攝氏度

      符號:J/(kg.℃)㈢水的比熱:4.2×103焦/(千克.℃)表示的含義是什么? ㈣比熱表的閱讀:

      得出:⑴水的比熱最大。(由此說明水作冷卻劑、保溫劑的作用)

      學(xué)智教育

      ⑵不同物質(zhì)的比熱是不同的。所以比熱是物質(zhì)的一種特性。與物質(zhì)的質(zhì)量、升高的溫度、吸放熱的多少無關(guān)

      ⑶不同狀態(tài)的同一種物質(zhì)的比熱不同,說明比熱與物質(zhì)狀態(tài)有關(guān)。

      【思考】比較水和砂、土的比熱大小,說說海洋和陸地會對氣候產(chǎn)生什么不同的影響? 【分析】我國一月和七月的平均氣溫分布圖,驗證猜想 【思考】海洋對沿海地區(qū)降水的影響

      【小結(jié)】海洋和陸地的性質(zhì)對氣溫和降水的影響:海洋和陸地的性質(zhì)不同,對降水和氣溫的影響不同。海洋使得氣溫變化小,降水豐富。

      四、地形對氣溫和降水的影響

      ⒈氣溫隨著地勢的升高而降低。一般海拔增高1000米,氣溫會下降約6℃。⒉山地的迎風(fēng)坡比背風(fēng)坡多雨,向陽坡比背陽坡氣溫高?!居懻摗繛槭裁从L(fēng)坡多雨,背風(fēng)坡少雨?

      五、季風(fēng)

      ⒈季風(fēng)是在不同的季節(jié)里風(fēng)向相反和接近相反的風(fēng)?!居懻摗坎⒂懻摻Y(jié)果填圖。

      ⑴同一緯度的大陸和海洋,冬季和夏季的氣溫分別是哪個高?(要求分析是什么原因所致:源于海洋和陸地的熱力性質(zhì)差異)

      ⑵這種溫度的季節(jié)性變化對氣壓高低分布有什么影響? ⑶大陸和海洋高氣壓和低氣壓的變化對風(fēng)向產(chǎn)生什么影響?

      ⒉世界上季風(fēng)區(qū)域很廣,以亞洲季風(fēng)最盛行。我國冬季盛行偏北風(fēng),夏季盛行偏南風(fēng)?!舅伎肌縋90的思考題 【小結(jié)】

      影響氣候的重要因素:緯度位置、海陸分布和地形、季風(fēng)等。軼事記錄

      學(xué)生對比熱的知識解釋生活中的現(xiàn)象很感興趣,科學(xué)知識深深地吸引著學(xué)生。實驗直觀明了,學(xué)生易于接受。

      學(xué)智教育

      課后反思

      本節(jié)內(nèi)容安排2課時。第一課時上至海陸分布對氣候的影響。

      第9節(jié)

      中國東部的季風(fēng)雨西部的干旱氣候

      教學(xué)目標(biāo)

      ⒈了解我國季風(fēng)氣候的類型和分布

      ⒉學(xué)會根據(jù)氣候資料分析我國季風(fēng)氣候的特點 ⒊學(xué)會根據(jù)氣候資料分析我國西部干旱氣候的特點 ⒋知道氣候變化雨動物行為的關(guān)系

      ⒌了解氣候?qū)θ祟惿a(chǎn)生活的影響,以及如流對氣候資源的利用 ⒍知道寒潮、臺風(fēng)、洪水等災(zāi)害性天氣的成因和危害

      ⒎關(guān)注人類活動對氣候的影響,初步建立人地和諧的氣候資源觀。重點難點分析

      重點:中國東部的季風(fēng)雨西部的干旱氣候的特點及對人類活動的影響;

      人類活動雨洪水;

      人類活動對氣候的影響

      難點:中國東部的季風(fēng)雨西部的干旱氣候的特點分析;

      人類活動與洪水 教、學(xué) 預(yù) 設(shè) 調(diào) 控 對 策

      一、東部季風(fēng)氣候

      1、季風(fēng)氣候區(qū)是指夏季風(fēng)能夠到達的地區(qū)。

      2、我國在大興安嶺-陰山-賀蘭山-岡底斯山一線以東以南的地區(qū)是季風(fēng)氣候區(qū)。分布有熱帶季風(fēng)氣候、亞熱帶季風(fēng)氣候和溫度季風(fēng)氣候。

      【討論】P91討論題得出:

      3、我國季風(fēng)氣候的主要特點:冬季氣溫低,降水少;夏季氣溫高,降水多,全年降水比較豐富。但南方冬季氣溫明顯高于北方,氣溫年較差小,年降水量更大。

      學(xué)智教育

      4、季風(fēng)氣候?qū)θ藗兩a(chǎn)、生活的影響有利有弊。

      A、降水充沛,集中夏季,四季分明,雨熱同期對農(nóng)業(yè)生產(chǎn)非常有利

      B、我國季風(fēng)氣候的大陸性強,降水的年際變化很大,使我國洪澇和旱災(zāi)頻發(fā)。C、冬季的低溫又常形成寒潮、凍害、暴雪等惡劣天氣。

      二、我國西部的干旱氣候

      ⒈夏季風(fēng)不能到達的我國西部地區(qū)一般降水稀少,為干旱各半干旱氣候區(qū)。

      ⒉我國西部的干旱氣候的特點:全年降水量稀少,降水集中在夏季,季節(jié)變化大;冬季寒冷,夏季炎熱,氣溫日較差、年較差很大,但日照充沛。(形成原因的分析:西部地區(qū)深居內(nèi)陸,海洋水汽難以到達。)

      ⒊干旱氣候的利弊:氣溫較差大,光照時間長,對農(nóng)業(yè)生產(chǎn)非常有利,如棉花、瓜果的生產(chǎn)。

      ⒋干旱氣候區(qū)的生物在行為和形態(tài)上的適應(yīng)性:如仙人掌粗大的莖和葉刺;抬尾芥蟲在大霧的夜里抬起屁股的做法。

      三、寒潮、臺風(fēng)和洪水

      1、寒潮是大范圍的強烈冷空氣活動。會帶來劇烈的降溫、霜凍、大風(fēng)和揚沙天氣。

      2、臺風(fēng)是一種破壞力很大的災(zāi)害性天氣?!居懻摗竣排_風(fēng)天氣的感受和自我防護知識 ⑵臺風(fēng)的利弊

      3、洪水是我國?最大的自然災(zāi)害之一。引發(fā)的原因:持續(xù)性的暴雨、臺風(fēng),人類活動?!緦嶒灐恐脖蛔o坡實驗 【為什么做】

      持續(xù)性暴雨和臺風(fēng)使引發(fā)洪水的主要自然原因。一些人類活動也可以引發(fā)洪水或使洪水的危害增大。隨著人類社會的發(fā)展,人類活動對洪水產(chǎn)生的影響越來越大。為什么會有這樣的說法?現(xiàn)實呈現(xiàn)在我們面前!譬如黃河上游植被的破壞,使黃河中下游地區(qū)頻頻發(fā)生洪澇災(zāi)害。由于上游泥沙的大量流失,黃河在下游也成為了地上河,使位于黃河下游的城市時刻處在洪水的威脅之中。讓我們來做這個實驗,初步而實在地體會一下植被對水土保持的作用。

      第四篇:初中英語全英教案

      A teaching plan

      教材分析 學(xué)情分析 Contents: 1.Vocabulary: 2.Structure: 3.Dialogue: 4.listening: Objectives:

      1.Teaching Aims and Demands(1)Instructional Objectives

      Be able to use the new words and phrases:

      (2)Ability Objectives Be able to use listening skills to comprehend their dialogues, such as listen for specific information etc.Be able to use what they learned to describe what they can do and give responses.Be able to use the language they learned to finish a dialogue and a short passage.(3)Educational Objectives

      Arousing students’ interest and helping them learn by using pictures.Building their confidence by step by step approach and careful scaffolding.2.Teaching Importance To master the key vocabulary

      To understand and use the target language To master the usage of the different forms of “can” in the target language.3.Teaching Difficulties To enable the students to understand the sentence patterns to talk about the ability activities.To enable the students to use the target language

      The students learned the structure “can do sth”, So it’s difficult and important to let them understand it can also be used to talk about the ability activities.4.Teaching Aids Multi-media computer, Tape recorder and so on.5.The Teaching Methods(1)Communicative teaching method.(2)Audio-visual teaching method.(3)Task-based teaching method.6.Studying Ways(1)Let the Ss pass “Observation—Imitation—Practice” to study language.(2)Let the Ss pay attention to the key information in listening practice.(3)Enable the Ss to study English language by Communication.(4)Let the Ss know that conclusions and being good at thinking are necessary to learn English well.Procedures and Time Allotment: 2 Task1: Warming-up(2mins)Before class, get Ss to enjoy an English song for about 2 minutes to warm them up.The purpose of the task-based activities is to Interest the students Task 2:Lead-in(3mins)1.Use the PPT to lead in the new lesson..show some pictures and teach the words and phrases: 2.ask Ss read the words together.Task3: Play a game(4mins)Task 4: Presentation(8mins)The purpose of the task-based activities is to let the students learn to cooperate with each other and practice the language points, improve the students’ abilities of speaking.Task5: Representations(5mins)Task 6.Listening(5mins)1.Ask Ss to open their books and turn to Page 59.Look at part 1b, look at the conversations and make sure the students understand the conversations and what to do.Then play the tape for three times.For the first time the students only listen to understand the whole general meaning of the conversations.For the second time the Ss pay attention to the activity in each conversation and write them in the blanks.For the third time the Ss pay attention to the time that the activities in each conversation are done and number the conversations(1-3).Ask some Ss to check their answers.2.Practice the conversations in 1b.Then make your own 3 conversations.The purpose of the task-based activities is to practice listening and improve the students’ abilities of listening.Task 7.Make a survey(7mins)

      Give the students several minutes to prepare the survey using the target language to ask and answer, next fill the form : Finally ask two groups of the students to report their results.For example: Task 8.Summary(4 mins)Summarize the key language points in groups , and show them on the screen to help the Ss take notes.Task 9.Homework(2mins)1.Consolidate and review the expressions of the lesson.2.Write a short passage about the results of the survey.Blackboard design

      第五篇:Module1-4全英教案

      Module1 The Great Wall

      1、Teaching preparing:

      Students book:Module1Unit 1Activity1, 2, 3

      2、Teaching task: A.basic object:

      Key words:

      thousand postcard more kilometer

      Key sentences: “These postcards are great!” “It?s a picture of the Great Wall.” “Tell me more about the Great Wall.” “How long is it?

      B.To learn “thousand

      kilometer

      million ” C.Review: The using way of the verb ?be? 2.

      Talking about some famous places.3、Teaching point: words: thousand

      kilometer

      million postcard

      more4、Teaching difficulty:

      kilometer

      thousand

      million

      “Tell me more about the Great Wall.“It?s a picture of the Great Wall.”

      5、Task design: words: postcard

      more

      thousand

      kilometer

      million

      Sentences: “These postcards are great!” “It?s a picture of the Great Wall.” “Tell me more about the Great Wall.” “How long is it?”

      “It?s about six thousand seven hundred kilometers.”的句型。B.The task:

      1:AB

      Unit1

      exercise3 2:AB

      Unit2

      exercise1、2、4、5

      6、Teaching things Photo radio picture wordcards 第一課時:

      1、Warm up ⑴Greetings: T—Ss Ss—Ss

      (2)Competition: List the places the visited as many as possible.2、Leading :(1)A.watch TV T: What’s this place?

      S:(teacher writes the main structure on board as modal for other students)It’s a picture of … B.Game : Tell me more T: It’s an animal.S1: Tell me more

      T: It has long nose.S1: It’s an elephant.The more “Tell me more”, the less will the score be given.3、(Presentation)(1)S open their books Question: Look at the pictures a.Who are they? b.Where are they? c.What are they doing? Student answer the questions.(2)listen to the tape(3)repeat after the tape.(4)Teacher explain the text and student practice the key points.a.The key points: postcard

      more

      thousand

      kilometer

      million b.The main sentences structure: “These postcards are great!” “It?s a picture of the Great Wall.” “Tell me more about the Great Wall.” “How long is it?”(6)students practice to make sentences with the key points.Game:Passing wordcards

      4、Drilling and Counselling(1)Finish the exercise one(2)Pairwork

      5、Teaching handwriting: “It?s a picture of the Great Wall.” “Tell me more about ……”

      三.課后反思:

      這堂課主要講了各個國家的一些名勝古跡,通過讓孩子描述圖片的內(nèi)容來掌握所學(xué)的句型.鍛煉他們的口頭表達能力,再讓他們自己帶一些圖片,同桌之間相互對圖片進行描述,加深對所學(xué)知識的記憶.單詞的掌握還欠缺一點.第二課時

      Step1.Tell students a joke and give them a riddle to fun.Step2.Review the words: postcard

      more

      thousand

      kilometer

      million

      Step3.Repeat the text after the tape, then students practice with partner in roles.Step4.Teacher explain the using way of “million” “thousand”: teacher give numbers, students tells “~ thousand” or “~ million”.6,000,000

      34,000

      12,000,000

      Step5.Homework: a.word dictation b.recite paragraph one c.Students make role play about unit one.第三課時

      Step1.a.Student make role play.b.Give words dictation.c.Open Activity Book.Step2.Do exercise 1.a.Students look at pictures, tell what they can see on it.Students describe.b.Students read the questions.c.Teacher gives help, students finish the question.Step3.Do exercise 2.Listen, ask and answer.a.Play the tape a second time, pauses it after each second.T: What are they? S: They are cars, trees.….b.Work in pairs, ask and answer.Step4.Do exercise 3 Complete the dialogues a.Students look at pictures, tell what they can see on it.Students describe.b.According to the pictures and words in the brackets,students fill the blank

      第2單元教案 New York is in the east of America.1Teaching preparing: Student?s book:Module1Unit 2Activity1, 2, 3

      2、Teaching task: A.Basic objects: Key words:Mexico

      Canada Key sentences: “It?s in the north / south / west / east of China/ America…”

      “Tell me more about the Great Wall.” “How long is it?” B.Review: The using way of verb ?be?

      2.Making student know about famous places.Talking about some basic facts of a country or a place,and learn to use direction words:It?s in the north / south / west / east of

      3、Teaching point: words:

      Mexico

      Canada

      San Francisco

      New York

      4、Teaching difficulty: How to pronounce “Mexico” “It?s a picture of the Great Wall.” “Tell me more about the Great Wall.”

      5、Task design Learning task: Review words:thousand

      kilometer postcard

      more

      million

      To learn vocabulary:San Francisco

      New York Mexico

      Canada

      Learning “It?s a picture of the Great Wall.” “Tell me more about the Great Wall.”

      “It?s in the north / south / west / east of China/ America…” “It?s about six thousand seven hundred kilometers.”

      6、Teaching things

      Radio

      wordcards

      photo

      picture

      第四課時

      1、Warm up ⑴Greetings: T—Ss Ss—Ss(2)Pointing game: Teacher gives students four cards “north / south / west / east”, let students put them around the classroom.T: North.S: Students point to the north

      2、(Leading)(1)A.Watch PPT T: What?s this place? S: It?s a picture of America.Students learn to read Mexico

      Canada

      San Francisco

      New York B.a.Game : Pointing game(Students open the book, look at activity 1)T: Mexico.S: Students point to the south of the map.c.Listen to the tape, and point to the places on the map.C.Lead in

      1)Student list Chinese famous cities, teacher write them on the black board.2)Teacher write the main structure on the board: “Tell me more about the …...” “Where is it?”

      “It?s in the north / south / west / east of China/ America…”

      “How long / big is it?”

      3)Students practice with partner

      3、(Presentation)(1)S open their books Question: Look at the pictures a.Who are they? b.What are they doing? Student answer the questions.(2)listen to the tape(3)repeat after the tape.4、(Drilling and Counselling)Learn the chant: a.What can you see? b.What can you see on the flag?

      Teacher introduce history of American flag.c.Students listen to the tape.e.Students repeat 5.Teacher?s handwriting: “It?s a picture of the Great Wall.” “Tell me more about ……”

      “It?s in the north / south / west / east of China/ America…”

      三.課后反思

      第五課時

      Step1 Warm up: Do the chant “America”

      Play a game:“What am I?”

      Rules: Students can do 1~2 actions.1 action got a star, 2 actions got 2 stars.The less actions , the more stars will be given.Step2 Do activity 3.a.Listen to the tape.b.Listen again, students claps hands, they can clap harder when hear the stressed words.c.Students repeat

      Step3 Do activity book Activity 1 a.T: what can you see?

      S: I saw….b.Ss read the words after teacher.c.Play the tape, students write the answer.Activity 2 a.Ss read the places with teacher?s help.b.Ss write sentences, teacher offers help.Step4 Homework 1.Do exercise 3 2.words dictation.課后反思:

      課本中出現(xiàn)了東南西北方位詞,雖然不是重點,但還是應(yīng)該拿出來給孩子們復(fù)習(xí)復(fù)習(xí).通過對這個模塊的一個小測驗,發(fā)現(xiàn)孩子們對基本知識的掌握不夠扎實.《英語》六年級第七冊第2模塊

      第1單元教案 Chinatown in America

      1Teaching preparing

      Students? book:Module2 Unit 1 Activity1, 2, 3

      2、Teaching task 2.Basic task Key words:miss

      sometimes

      restaurant

      really Key sentences“There?s a Chinatown in New York!” “There are lots of Chinese shops and restaurants there”.B know about “l(fā)ots of”

      C.Review:

      The using way of the verb ?There be? 2.To describe places

      3、Teaching point:

      dancing

      words:

      sometimes

      restaurant

      really Teaching difficulty How to pronounce words ?sometimes

      restaurant? To learn the structure “There be”

      5、Task design A.Learning task Key words: miss

      sometimes

      restaurant

      really

      dancing

      Key structure: “There?s a Chinatown in New York!”

      “There are lots of Chinese shops and restaurants there”.B.:Task 1:AB Unit1 exercise3

      2:AB Unit 2 exercise1、2、4、5

      3: Play a game: Students should prepare a piece of paper

      第一課時

      1、Warm up ⑴Greetings: T—Ss Ss—Ss

      (a.)Student talk about there weekend: T: I bought some fruits, can you guess What did I buy? S:Did you buy…..2 Leading(1)A.Teacher show a peach(card)on the blackboard, “What can you see?” S: A peach.Teacher help the students say: There is a peach.(b.)Students make sentences with “ There is a …..”

      (c.)Teacher show two peaches and teach “ There are …(n+s/es)”(d.)Students make sentences with “ There are …(n+s/es)” Watch POWERPOINT T: What?s this place?

      S:(teacher writes the main structure on board as modal for other students)There is/are ….in/on….B.Game : The Six boxes

      a.Students draw six big boxes on a piece of paper.b.Tell them to number the boxes ?1—6? c.Teacher ells what to draw in the boxes: In box 1 there is a pen.In box 2 there are two erasers.In box 3 there is an apple.In box…… C.Lead in

      1)T: I describe a place, you guess.if you don?t know, you ask “ tell me more!” students guess out it?s Chinatown, teacher Show PPT about Chinatown.2)Ask students to describe with sentence structure “There be” given on the blackboard.3、Presentation(1)S open their books Question: Look at the pictures c.Who are they? d.Where are they? c.What are they doing? Student answer the questions.(2)listen to the tape(3)repeat after the tape.(4)Teacher explain the text and student practice the key points.a.The key points: miss

      sometimes

      restaurant

      really

      dancing

      b.“ There is a …..”

      “ There are …(n+s/es)”

      (6)students practice to make sentences with the key points.Game:passing wordcards

      make sentences

      4、Drilling and Counselling(1)Finishing activity book exercise 3.(2)Students help each other.5、(Task-fulfilling)Guessing game:”Where do you go on weekend?” 6.Teachers handwriting:

      There

      is

      a

      (n)

      There

      are

      (ns/es)

      第二課時

      Step1.Tell students a joke and give them a riddle to fun.Step2.Review the words: miss

      sometimes

      restaurant

      really

      dancing

      Step3.Repeat the text after the tape, then students practice with partner in roles

      Step4.Game a.Revise ?north? ?south? ?west? ?east? with the students.b.Tell the students to draw a big circle on a piece of paper.(tell them that the circle is an island and that you are going to describe the contents the island and and they have to draw the objects in the correct places.c.T:(draw a large island on your paper)In the north there is a river.In the south there are two mountains.In the west there are some trees.In the east there is a house.Step5.Homework: d.word dictation e.recite paragraph one f.Students make role play about unit one.Step6.課后反思

      第三課時

      Step1.a.Student make role play.b.Give words dictation.c.Open Activity Book.Step2.Do exercise 1.a.Play the recording again, then encourage them to tell the important things in the story.b.For each question invite a student to come to the blackboard and write the sentence.Step3.Do exercise 4.Look at the pictures.Write sentences.a.students draw things that they know how to say in English and be similar to the ones in the book.b.Collect all the pictures from the class.c.Students A and B, give A a picture , A describe the picture and B draw it.d.Show the picture, if student B draws the same object, he/she gets a point.Step4.Do exercise 3 Complete the dialogues a.Students look at pictures, tell what they can see on it.Students describe.b.According to the pictures and words in the brackets,students fill the blank

      第2單元教案

      Postcards from China

      Teaching preparing 1.Teaching task Students book:Module2Unit 2Activity1, 2, 3 Teaching objects 2.

      A.Basic task Key words:

      bicycle mountain lake square Key sentences: “There are lots of bicycles in China” “There is a very famous river” B.Review:

      The using way of the verb ?There be?

      2.Use the structure to introduce famous places

      For example: learn to use ?There be?

      to describe some basic facts of a country or a place

      3、Teaching point: Key words: bicycle mountain lake square

      4、Teaching difficulty: How to pronounce? square.? How to use ?there be?

      5、Task design: Learning task: Review words: miss

      sometimes

      restaurant

      really

      dancing

      To learn words: bicycle

      mountain

      lake square

      To learn “There are lots of bicycles in China” “There is a very famous river”

      6、Teaching things: radio photo wordcards picture 7.課后反思

      第二課時

      1、Warm up ⑴Greetings: T—Ss Ss—Ss(2)Chant” America”

      (3)Play a game to review the structure.2、Leading :(1)A.Watch PPT T: What?s this place?

      S: It?s a picture of the Changjiang River.The Tian?anmen Square.The West Lake.The Huangshan Mountain

      The Great Wall.a.Students learn to read them.b.Student describe them with “There is/are…..” B.Lead in

      a.)Listen to the tape, and number the places.b.)Students repeat after the tape sentence by sentence.c.)Students try to recite the paragraph with teacher?s help, the students who have tried will get a sticker.3)Students practice with partner 3 Presentation:(1)Ss do exercise 2 Now point and say(2)Ss do exercise 3 Listen and repeat, pay attention to the stress.a.Play the tape and pause after the first sentence.b.Repeat the activity with various actions, e.g., standing up, waving arms…

      4、Drilling and Counselling Learn the song: “There?s a Great Wall in China” a.Students listen to the tape.b.Students repeat

      三.課后反思:

      第五課時

      Step1 Warm up:

      Sing the song: “There?s a Great Wall in China”

      Play a game:“Memory”

      Rules: a.Students are divided into boys group and girls group.b.Give them limited time to memory the pictures, then they close the book.c.Students describe the objects in their memory, the more correct object they give, the more scores they will gain.Step2 Do activity book Activity 1 Listen and number.a.T: what can you see?

      S: I can see there is/are…(Students try to describe the pictures)b.Teacher describe the pictures, students number.Step3

      Activity 4 Look and complete the postcard.c.Ss draw the places with teacher?s describing.d.Ss write sentences, teacher offers help.Step4 Homework 1 Do exercise 3 2 words dictation.課后反思:

      由于學(xué)生個體差異的不同,課堂上的內(nèi)容對有些孩子比較容易,而對個別學(xué)生來說有很難,甚至不能聽懂.但我是不會讓一個孩子落后的.六年級的內(nèi)容也增加了,教學(xué)內(nèi)容就要做合理的調(diào)整和補充,同時根據(jù)學(xué)生的心理特點,有區(qū)別有重點的調(diào)整才行.《英語》六年級第七冊第3模塊

      第1單元教案 Collecting stamp is my hobby

      Teaching preparing: 1.Students book:Module3Unit 1Activity1, 2, 3 Teaching task: 2. Knowledge : A.Basic task: Key words:another collect

      stamp

      hobby

      men

      Key sentences: “I?ve got lots of stamps.”

      “These are some stamps from Canada ”.“ This stamp is from China”

      B.Review:

      The using way of ?be from? 2. Make students talk about hobbies.3、Teaching point: Key words:

      collect

      stamp

      hobby

      men

      women

      another

      4、Teaching difficulty: A.; men and man B;collect

      5、Task design: A.Learning task:

      To learn words: collect

      stamp

      hobby

      men

      women

      another To learn the structure: “I?ve got lots of stamps.”

      “These are some stamps from Canada ”.“This stamp is from China” B.To use the task: 1:AB Unit1 exercise 3 2:AB Unit2 exercise 1、2、4、5 3:You do action and I guess.4 : “Your hobby is doing….”

      第一課時

      1、Warm up ⑴Greetings: T—Ss Ss—Ss

      (2)Game: you do action and I guess.(3)Write down the sentence: Your hobby is doing sth Exercise “Your hobby is….(3)Free talk: Student talk about their hobbies: T: My hobby is reading books, what?s your hobby?(My hobby is doing sth)S:My hobby is …..2、Leading :

      (1)A.ask “What can you see? What?s this? ” S: It?s a stamp.T: What are these? S: These are some stamps.How to use :a stamp

      and some stamps Teacher help the students say: This stamp is from….(b.)Students watch PPT and make sentences with “This stamp is from….” “These stamps are from…”

      (c.)Teacher shows some stamps and teach “These stamps are from…”

      (d.)Students make sentences with “These stamps are from…” B.Game : Guessing game Students watch PPT

      T: What?s are these? S: These are stamps.Teacher give numbers to each stamp, then describe the picture of one of them, Students guess which number it is.T: This one has got a… on it.S: Number 3.Then reverse.C.Lead in T: Everyone has hobby, now listen to the tape , find out what Simon?s hobby is.3、(Presentation)(1)S open their books Question: Look at the pictures e.What?s Simon?s hobby? f.Where are the stamps from? c.Has Simon got any stamps from China? Student answer the questions.(2)listen to the tape(3)repeat after the tape.(4)Teacher explain the text and student practice the key points.a.The key points: collect

      stamp

      hobby

      men

      women

      another b.Students practice to make sentences with the key points.c.Game:Passing wordcards make sentences

      4、(Drilling and Counselling)(1)Finish SB U1 exercise3.(2)Pairwork.6.Teaching handwriting:

      “This stamp is from….” “These stamps are from…”

      三.課后反思:

      第二課時

      Step1.Game: Extend the sentence T: I?ve got lots of apples.S1: I?ve got lots of apples and bananas.S2: I?ve got lots of apples, bananas and pears.…….Step2.Review the words: collect

      stamp

      hobby

      men

      women

      another

      Step3.Repeat the text after the tape, then students practice with partner in roles

      Step4.Talk about stamps(SB book activity 3)a.Number those stamps.b.Teacher describe one of the stamp with the main sentence structure given on the blackboard: “This stamp is from….”.“It has got …..on it”.Step5 Homework: g.word dictation h.recite paragraph one i.Students make role play about unit one.Step6.課后反思

      第三課時

      Step1.a.Students make role play.b.Give words dictation.c.Open Activity Book.Step2.Do exercise 1.e.Play the recording again, then encourage them to tell the important things in the story.f.Then, tell them to read the sentences in the exercise and decide if they are ?True?, ?False? or ?Don?t know?.(Explain that they should tick ?Don?t know? if the answer is not found in the dialogue.)

      Step3.Do exercise 2.Now correct the false statements.Student A read the first false statement in Exercise1.Student B corrects.Step4.Do exercise 3 Complete the dialogues a.Students look at pictures, tell what they can see on it.Students describe.b.According to the pictures and words in the brackets, students fill the blank

      Step5.課后反思

      第2單元教案

      I’ve got a hobby

      Teaching preparing:

      2、Studends book:Module2Unit 2Activity1, 2, 3

      2、Teaching task: 2.Basic task:

      To learn to speak the structure: “Have you got any dolls from Japan ” “Yes, I have./ No, I haven?t” B.Review: Grammer 2.Talking about your hobbies.3、Teaching difficulty: any/some

      5、Task design: Review words: collect

      stamp

      hobby

      men

      women

      another To learn “Have you got any dolls from Japan ” “Yes, I have./ No, I haven?t”

      6、Teaching things: Radio

      photo

      picture

      wordcards 第四課時

      1、Warm up ⑴ Musical game “What?s your hobby?” “ My hobby is doing sth”(3)Watch PPT T: Students please watch PPT, What are these?

      Can you guess what Miss Ma?s hobby is? S: Your hobby is flying kites.(PPT explains some kites and any kites)T: Yes, have you got any kites? “Yes, I have/ No, I haven?t” 2Leading :(1)A.Ask and answer T: Have you got any books? S1: Yes, I have/ No, I haven?t.Have you got any ….s? S2: Yes, I have/ No, I haven?t.Have you got any ….s? B.Practice a.)Go through all the pictures with the students to make sure that they know the vocabulary.2)Teacher write the main structure on the board: “Have you got any…..” “Yes, I have./ No, I haven?t” 3)Students practice with partner

      3、Presentation: Ss do exercise 3 Listen and repeat, pay attention to the stress.a.Play the tape and pause after the first sentence.b.Repeat the activity with various actions, e.g., standing up, waving arms…

      4、Drilling and Counselling Learn the chant: “HOBBY” a.Students listen to the tape.b.Students repeat

      第五課時(REVIEW)Step1 Warm up:

      Sing the song: “HOBBY”

      Step2 Do activity book Activity 1 Listen and answer the questions.Step3

      Activity 3 Answer the questions.a.Students complete the questions according to their own situation.b.Students work in pairs:

      A keeps the book open and asks questions B closes his book and answer A?s questions.c.They exchange the roles.Step4 Homework e.Do exercise 3 f.words dictation.課后反思:

      本單元的內(nèi)容涉及到 my hobby(我的愛好),讓孩子準(zhǔn)備的課堂用具孩子沒能做充分的準(zhǔn)備.因此在課堂上孩子們談?wù)撜f的時間就縮短了.另外重點句型的操練,孩子們也很快的領(lǐng)會了.Module Four Happy Thanksgiving!

      Teaching preparin 1. Student book:Module1Unit 1Activity1, 2, 3

      2、Teaching task: 2.Basic task: Key words: festival

      special

      meal

      sound Key sentences:

      “What do you do on …..”

      “Thanksgiving is my favorite festival.”

      “We say ?thank-you? for our food, family and friends.”

      C.Review: “Can you tell me more about…..”and“… is my …”

      3、Teaching point: Words : festival

      special

      meal

      sound

      4、Teaching difficulty festival sound “Thanksgiving is my favorite festival.” “We always have a special meal.”

      5、Task design:

      To learn words :festival

      special

      meal

      sound

      To learn sentences: “What do you do on …..” “Thanksgiving is my favorite festival.” “We always have a special meal.”

      “We say ?thank-you? for our food, family and friends.”

      1:SB Unit 1 exercise2、3

      2: AB Unit 1exercise 1、2、3、4、5

      6、Teaching things radio photo wordcards picture

      第一課時

      1、Warm up ⑴ Sing a song “We wish you a merry Christmas.” Competition: List festivals as many as possible.2 Leading :(1)a.(Watch PPT— pictures about Chinese festivals)Ask questions: “what is this festival?”

      “What do we do at that festival?” b.Then show the PPT of main sentence structures: “… is my favorite festival, we always do(something)”

      Students look at pictures and talk about festivals in pairs with the main structures offered.c.Students show there ideas with their partner.B.Lead in

      1)T: You know much about Chinese festival, how many western festival do you know? Students list the western festivals.T: Very nice!Today Simon will tell us more about American festival, listen to the tape and later you must tell me about them.3、Presentation:(1)S open their books Question: Look at the pictures a.Who are they? b.What can you see? Students answer the questions.(2)Give the questions: “What are the two American festivals in the story?” “What do people do on Flag Day?” “What do people do on Thanksgiving Day?”(3)Answer the questions.4、Drilling and Counselling(1)Game: Guessing(T vs Ss)a.Prepare three word cards: Thanksgiving Day

      Flag Day

      Christmas Day b.Teach them to read.c.Teacher describes the activities that people do in different festival.T: You can see Christmas trees.Ss: Christmas Day 6.Homework: a.Write the new words.b.Collect Chinese and American festival information.第二課時

      Step1.Game: Guessing(Ss1 vs Ss2):

      Repeat the text after the tape, then students practice with partner in roles.Step2 Discussion

      Step3.Students make role plays about western festivals with their partner.Step4.Homework: a.word dictation b.recite paragraph two

      : 第三課時

      Step1.Give words dictation

      Step2.Open Activity Book, do exercise 1: Listen to the story again and tick or cross.a.Students read the questions.b.Students look at pictures, tell what they can see on it.Students describe.c.Teacher gives help, students finish the question.d.Play the tape, students finish the exercise.Step3.Do exercise3.Complete the table.a.Review “ I,me,we,our” b.Complete the table

      Step4.Do exercise Write about Spring Festival.a.Students look at pictures, tell what they can see on it.Students describe.Ss: Watch TV Talk with each other.Play games.Lesson four

      What’s your favorite festival?

      1、Teaching preparing:

      Teaching task: Student book: Module1Unit 2Activity1, 2, 3

      2、Teaching task :

      Basic task:

      Key words:lantern

      race

      moon cake

      Key sentences: “What?s your favorite festival?”

      “My favorite festival is ……” 3

      Teaching point: :

      Lantern Festival

      Spring Festival

      Mid-Autumn Festival Dragon Boat Festival

      race

      moon cake “What?s your favorite festival?”

      “My favorite festival is ……”

      4、Teaching : lantern, moon

      5、Task design: To learn words :

      festival

      special

      meal

      sound To learn sentences: Lantern Festival

      Spring Festival

      Mid-Autumn Festival

      Dragon Boat Festival

      race

      moon cake

      二、1、Warm up ⑴Greetings: T—Ss

      Ss—Ss(2)Do the chant, review “I, me, we, our”(3)Play a matching game:

      Thanksgiving Day

      Sing flag song

      Flag Day

      Receive presents

      Christmas Day

      Cheat each other

      Ask volunteers to finish the matching.(4)Ask students to add more activities.2、導(dǎo)入(Leading)(1)A.1Watch PPT

      T: What?s this festival? S: It?s ……

      Students learn to read Lantern Festival

      Spring Festival

      Mid-Autumn Festival

      Dragon Boat Festival B.Game: Guessing game

      T:(mimes rowing a boat)S: Is it Dragon Boat Festival? T: Right!b.Students do practice in pairs: choose a festival, ask and guess.3、Presentation:(1)S open their books(2)listen to the tape

      (3)Replay sentence by sentence(4)Students repeat after each sentence.(5)Students try to recite one of the festival.4、Drilling and Counselling StudentA chooses a festival, studentB asks and if he or she can?t guess out, he can ask “Tell me more.” unless he got the answer.第五課時

      Step1 Warm up: Play a game:“Sentence passing”

      Rules: Students ask and answer one to the next to review:

      “What?s your favorite festival?”“My favorite festival is ……”

      Step2 Do activity 3.Listen and repeat, pay attention to the stress.a.Play the tape and pause after the first sentence.b.Repeat the activity with various actions, e.g., standing up, waving arms…

      Step3 Do Activity Book Activity 1 Listen and complete the sentences.a.T show many pictures, if they like the picture they stand up and teacher count: “X students like…”;if they don?t like they remain seated.a.Ss read the questions with teacher?s help.b.Ss write sentences, teacher offers help

      Homework 1.Do exercise 4 2.words dictation.課后反思:

      通過對本單元的小測驗,孩子們對這節(jié)課的知識掌握的還不錯.孩子們也已經(jīng)知道了外國節(jié)日和中國節(jié)日不同.有的孩子上網(wǎng)查了許多關(guān)于節(jié)日的資料,在班里和其他的孩子一起分享.

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