一、考题回顾

题目
一、考题回顾

二、考题解析
【教学过程】
环节一:课堂导入
【提出问题】日常生活中在水中不断的加入糖会有什么现象产生?
【学生回答】在水中不断的加入糖,开始不断溶解,后来就不再溶解。
【教师引导】为什么不断加入糖之后,会出现不再溶解的现象?接下来就探究“饱和溶液”的内容。
环节二:新课教学
【教师引导】向盛有20mL水的烧杯中加入5g氯化钠,搅拌;等溶解后,再加5g氯化钠,搅拌,观察现象。然后再加入15mL水,搅拌,观察会产生什么现象?
【学生实验】学生按照设置好的活动小组,根据任务安排进行动手实验。
【学生回答】向盛有20mL水的烧杯中加入5g氯化钠,搅拌,氯化钠全部溶解。等溶解后,再加5g氯化钠,搅拌,氯化钠部分溶解。然后再加入15mL水,搅拌,未溶解的氯化钠继续溶解。
【教师引导】在室温下,向盛有20mL水的烧杯中加入5g硝酸钾,搅拌;等溶解后,再加5g硝酸钾,搅拌,观察现象。
【学生实验】学生按照设置好的活动小组,根据任务安排进行动手实验。
【学生回答】向盛有20mL水的烧杯中加入5g硝酸钾,搅拌,全部溶解。等溶解后,再加5g硝酸钾,搅拌,硝酸钾部分溶解。
【教师引导】当烧杯中硝酸钾固体有剩余而不再继续溶解时,加热烧杯一段时间,观察剩余固体有什么变化。然后再加入5g硝酸钾,搅拌,观察现象。待溶液冷却后,又有什么现象发生?
【学生实验】学生按照设置好的活动小组,根据任务安排进行动手实验。
【学生回答】加热烧杯后,剩余固体全部溶解。再加入5g硝酸钾,也全部溶解。待溶液冷却后,有晶体析出。
【教师总结】在一定温度下,向一定量溶剂里加入某种溶质,当溶质不能继续溶解时,所得到的溶液叫做这种溶质的饱和溶液;还能继续溶解的溶液,叫做这种溶质的不饱和溶液。
【教师提问】请学生根据对饱和溶液和不饱和溶液含义的理解,对上述实验中溶液的状态试着举例说明。
【学生回答】向盛有20mL水的烧杯中加入5g氯化钠,搅拌,氯化钠全部溶解。等溶解后,再加5g氯化钠,搅拌,氯化钠只有部分溶解,此时是饱和溶液。然后再加入15mL水,因为又能继续溶解氯化钠,所以此时为不饱和溶液。
【教师提问】通过以上实验操作,如何由不饱和溶液变成饱和溶液?
【学生回答】①加入溶质;②降温。
【教师引导】如何由饱和溶液变成不饱和溶液?
【学生回答】①增加溶剂;②升温。
【教师说明】只有指明“在一定量溶剂里”和“在一定温度下”,溶液的“饱和”和“不饱和”才有确定的意义。
环节三:巩固提高
1.在大箩卜上挖一个孔,向其中注入饱和食盐水,一段时间后,将食盐水倒出来,在相同温度下,发现在倒出的溶液中还可以溶解少量食盐。这说明( )。
A.倒出的溶液是饱和溶液 B.倒出的溶液是不饱和溶液
C.原溶液中溶剂多了 D.原溶液中溶质少了
【答案】AC。
环节四:小结作业
学生总结归纳本节课所学主要知识,表述学习心得。
作业:思考“某溶质的饱和溶液一定是浓溶液吗?”。
【板书设计】

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第1题:

一、考题回顾



答案:
解析:
二、考题解析
【教案】
Teaching aims:
Knowledge aim:
Students will master the meaning and pronunciation of the words.
Ability aim:
Students will know how to pronounce “ch” and “sh” in words.
Emotional aim:
Students will be interested in learning English.
Key and difficult point:
Key Point:
Students will master the meaning and pronunciation of the words.
Students will know how to pronounce “ch” and “sh” in words.
Difficult Point:
Students will be interested in learning English.
Teaching procedure:
Step 1: Warming-up
1. Greetings. Talk about the weather.
2. Chant with the students



Ask them if they remember the first step in the chant. They may say that it is to “wash” the tomato. Then tell them that today we are going to learn some pronunciation in it.
Step 2: Presentation
1. Draw some pictures according to different words, and then explain the meanings to the students.
2. Play the finger show with the students to consolidate the words. For example, finger 1 refers to “chicken”, and finger 2 refers to “lunch”. When the teacher points finger 1, the students should read “chicken” loudly. The rest could be done in the same manner.
3. Ask students to find similarities and differences among the words. They may say that in the first two words, there is “ch” in the words, while in the last two words, there is “sh” in the words. And they pronounce similarly.
4. Conclude the rules of “ch” and “sh”. Tell them that when they see “ch”, they should pronounce [t?], and when they see “sh”, they should pronounce [?]. They may sound similar, but they are different. Please be notice that.
Step 3: Practice
1. Ask a few students if there are other words containing “ch” or “sh”. They may answer “chopsticks”, “ship” or “shop”.
2. Read the words in a different order, and ask students to rank the words according to the listening. At the same time, invite one students to come to the front and write the words down on the blackboard. Check answers later.
Step4: Production
Ask students to make up dialogues with their deskmates. 5 minutes will be given. After that, invite 2 pairs to share their dialogues. Give encouragement.
Step5: Summary and Homework
Summary: Ask a student to conclude the content of the lesson and summarize with the whole class.
Homework: Read the words to their parents.
Blackboard design:



【答辩题目解析】
1. What will you do to help students master the pronunciation of what we need to learn?
【参考答案】
First, they should know how to pronounce the syllables. So I will pronounce them in a clear way to make sure that they notice the place of articulation. I will correct their pronunciations if they make some mistakes. Then, I ask them if they know other words sharing the same syllables. Also, few activities were arranged to make them really use the rules. So I believe they will master the rules of the pronunciations.
【答辩题目解析】
2. What will you do if the students can’t focus on your class?
【参考答案】
There are some options to deal with the problem. First, I could arrange some interesting activities to stimulate their interest. Second, when imparting some knowledge, I could show some examples closely related to their daily lives. They will be interested in familiar things. Third, I could ask some students to answer my questions from time to time, so they will be more focused in case of being asked. So I will try to use the most appropriate method to attract their attention.