问题 选择题

列现象能证明分子在化学变化中可分的是(  )

A.100 ml水和 100 ml酒精混合后总体积小于200 ml

B.打开盛装浓盐酸瓶盖,浓盐酸逐渐减少

C.气态氧在加压降温时变为淡蓝色的液态氧

D.加热氧化汞得到银白色的汞和氧气

答案

A、100ml水和100ml酒精混合后总体积小于200ml的过程中,没有新物质生成,属于物理变化,不能证明分子可分,故选项错误.

B、浓盐酸具有挥发性,打开盛装浓盐酸瓶盖,浓盐酸逐渐减少的过程中,只是状态发生改变,没有新物质生成,属于物理变化,不能证明分子可分,故选项错误.

C、气态氧在加压降温时变为淡蓝色的液态氧的过程中只是状态发生改变,没有新物质生成,属于物理变化,不能证明分子可分,故选项错误.

D、加热氧化汞得到银白色的汞和氧气,属于化学变化;在此过程中氧化汞分子分解成汞原子和氧原子,氧原子之间结合成氧分子,汞原子直接聚集成金属汞;能证明在化学反应中分子可分;故选项正确.

故选D.

阅读理解

Martha had been working for Miller Laboratories for two years,but she was not happy there.Nothing significant had happened in the way of promotions or salary increases.Martha felt that her supervisor,a younger and less experienced person than she,did not like her.In fact,the supervisor often said unpleasant things to her.

One day,while talking with her friend Maria,she mentioned how discouraged she was .Maria gave her the name of a cousin of hers who was director of Human Resources Department for a large chemical company.Martha called him the next day and set up an interview on her lunch hour.

During the interview,Mr Petri said,“You're just the kind of person we need here.You've being wasted in your other job.Give me a call in a day or two.I'm sure we can find a place for you in our organization."Martha was so happy that she almost danced out of the building.

That afternoon,Ruth Kenny,her supervisor,saw that Martha had come in ten minutes late from her lunch hour and she said ,“Oh,so you finally decided to come back to work today?"

This was the last straw.She could not take another insult.Besides,Mr Petri was right: she was being wasted in this job.

“Look," she said angrily,“if you don't like the way I work,I don't need to stay here.I'll go where I'm appreciated!Goodbye!"She took up her things and stormed out of the office.

That night she called Maria and told her what had happened and then asked Maria.“What do you think?"

“Well,"said Maria carefully,“are you sure about the other job?"

“Well,not exactly,but..."

Maria continued ,“Will you be able to get a recommendation from Ms Kenny if you need one?"

“A recommendation?…from Ms Kenny?"hesitated Martha,in a worried tone.

“Martha,I hope you didn't burn your bridges,”Maria said.“I think I would have handled it differently."

1.Martha is unhappy in her job because_________.

A.she has not advanced

B.the work is not significant

C.her supervisor is younger than she

D.there is too much work with little payment 

2.Which of the following statements is NOT true?

A.At her supervisor's criticism,Martha lost her temper.

B.Mr Petri felt Martha was not valued in her present job.

C.Martha's interview with the director was on her lunch hour. 

D.Martha got the name of the director through her cousin. 

3.The phrase “the last straw"in the middle of the passage probably refers to _________.

A.the last opportunity

B.the straw that saves Martha's life

C.the last reminder

D.the final unpleasant thing 

4.What does Maria think of Martha's decision?

A.Martha has handled the matter properly.

B.Martha shouldn't have set the bridge on fire.

C.Martha should have found a new job before leaving.

D.Martha shouldn't have lost her temper with her supervisor. 

单项选择题