问题 填空题

做电解水的实验时,要给水通______电.正极玻璃管内得到的气体是______,验证方法是______;负极玻璃管内得到的气体是______,验证的方法是______.电解水反应的化学反应表达式是______,反应类型属于______反应.

答案

电解水实验要用直流电源,在电解水实验中,可观察到的现象有:正极的气体体积少,能使带火星的木条复燃,负极的气体体积多,能燃烧,而且体积多的是少的二倍.根据以上现象可推出正极产生的气体是氧气,负极产生的气体是氢气,还能进一步推出水由氢元素和氧元素组成,该变化是化学变化,可用文字式表示为水

通电
氢气+氧气,该变化是由一种物质变成多种物质的反应,属于分解反应.

故答案是:直流、氧气、使带火星的木条复燃、氢气、点燃能燃烧、水

通电
氢气+氧气、分解.

阅读理解

阅读理解。

     When I was about twelve years old, a girl in my class liked to point out my disadvantages.

      Week by week her list grew: I was very thin; I wasn't good at math; I talked too much; I was too

proud, and so on. At last, I became very angry. I ran to my father with tears in my eyes.

     He listened to me quietly, and asked, "Are those things true or not? Jane, didn't you ever think about

what you're really like?" Then he added, "Well, you have that girl's opinions. Make a list of everything she

said and mark the points that are true."

     I did as he told me. To my great surprise, I found out that about half the things were true. Some of them

I couldn't change, like being very thin, but many I could -and suddenly I wanted to change. For the first time

I got a clear picture of myself.

     I brought the list back to Daddy, and he said, "Now you know better about yourself. But you have to

learn to listen, not just close your ears angrily and feel hurt. When something said about you is true, you'll

find it will be of great help to you. Don't shut your ears. Listen to the truth and do what you know is the

right thing to do."

     Daddy's advice has returned to me at many important moments. In my life, I've never had a better piece

of advice.

1. When the writer Jane was _______, a girl in her class liked to point out her shortcomings.

A. about 10

B. about 12

C. about 14

D. about 16

2. Jane thought she couldn't change one thing. It was that ________.

A. she was very thin

B. she wasn't good at math

C. she talked too much

D. she was too proud

3. Who change the writer's opinion?

A. father

B. mother

C. sister

D. brother

4. What did Jane's father really mean by saying "Make a list of everything…"?

A. Make a shopping list.

B. Forget it.

C. Finding out what is right and what is wrong.

D. Don't make friends with the girl.

5. Which of the following is the best title for this passage?

A. My Father

B. My Life

C. My Teacher

D. The Best Advice

填空题