问题 选择题

推理是化学学习中常用的一种方法.下列推理中,不合理的是(  )

A.任何物质导电时,都一定发生了电离过程

B.若确定某种物质中含有两种元素,则还不能确定该物质一定是化合物

C.CO2和Na2O2反应产生O2,Na2O2可用于潜艇或航天器中生产O2

D.Fe与CuCl2溶液反应置换出Cu,则可推断Fe金属活泼性比Cu强

答案

A.熔融或水溶液中电解质的导电发生电离过程,电解质电离出自由移动的离子,可导电,但金属晶体导电没有发生电离,故A错误;

B.某种物质中含有两种元素,可能为化合物,也可能为混合物,故B正确;

C.CO2和Na2O2反应产生O2,潜艇或航天器中常用过氧化钠可与二氧化碳反应生成氧气,可作为氧气的来源,故C正确;

D.根据活泼金属可置换出不活泼金属的反应特点可知Fe与CuCl2溶液反应置换出Cu,则可推断Fe金属活泼性比Cu强,故D正确.

故选A.

阅读理解

When you are feeling unhappy or forget how great you are,these are six ways to make you feel good about yourself.

1)Look in the mirror and say to yourself,“I am a special person and there's no one  in the world like me.I can do anything!” It may not sound so good,but it really works !

2)Do something nice for someone.Helping others always makes you feel good.

3)Smile! Be friendly to people you meet.Look for the good things in your friends and family.

4)Learn something new! Have you always wanted to decorate your own room or learn how to swim? Go for it! New challenges(挑战)are fun and give you a sense of accomplishment (成就感)when you have finished.

5)Read and start a diary.Turn off the TV and let your imagination(想象)fly! Write down your thoughts,dreams or anything you want! Writing always helps to express your feelings.

6)Stay with your family.We all need our family time.Talk with your Mum or Dad or maybe even your cousin.

小题1:You may see this passage in ____________.

A.a science book

B.a story book

C.a magazine

D.school rules小题2:According to the passage , new challenges ______when you finish them.

A.are fun

B.make you feel confident

C.are dreams

D.both A and B小题3:Which of the following should you say “NO” to when you are unhappy?

A.You should always look for the good things of others.

B.Stay alone at home as much as possible.

C.Learn something new and go for it!

D.Keep a diary to express your feelings.小题4:The best title(标题)for the passage is_______.

A.Do Your Best

B.Six Ways to Feel Good about Yourself

C.It's Never too Late to Learn

D.Always Smile to Your Life

单项选择题