问题 选择题

下列说法中正确的是(  )

A.常温常压下,11.2 L氯气所含有的原子数为6.02×1023

B.常温常压下,28 g氮气所含有的原子数为6.02×1023

C.同温同压下,相同体积的任何气体单质所含的原子数目相同

D.在标准状况下,0.5×6.02×1023个氧气分子所占的体积为11.2 L

答案

A.氯气不是在标况下,体积不是11.2L,故A错误;

B.28 g氮气的物质的量是1mol,一个氮气分子里有2个原子,28g氮气所含有的原子数为1.204×1024,故B错误;

C.同温同压下,相同体积的任何气体单质的物质的量相同,但是气体单质分子中所含的原子数不一定不同,故C错误;

D.0.5×6.02×1023个氧气分子的物质的量是0.5mol,在标准状况下下的体积是11.2 L,故D正确.

故选D.

完形填空

阅读下面短文,按照句子结构的语法性和上下文连贯的要求,在空格处填入一个适当的内容(不多于3个单词)或者用括号中词语的正确形式填空。

Two things I did may have caused people     小题1:  (think) that something is wrong with me. The first was when my wife asked me to have the sitting room clock     小题2:   (repair). I drove into the market place of our little town and, clock under arm, entered a shop. Only it was the meat shop,     小题3:   my thoughts far away, I stood staring into the shopkeeper's eyes. I   小题4:  (be) his customer for a long time and the good man smiled at me.

This went on for several very long seconds before I realized where I was. There is no doubt that I should have calmly bought a pound of meat, 小题5:    I merely nodded briefly and left.

The other man in my town who probably thinks I am mad is Mr. Smith. Some years ago he was manager of Mead's Shop, and he and I knew each other quite well. One day he     小题6:   (stand) in the doorway of his shop when I passed.My brain was on some distant problem and my eyes stared into space.

“Hello, Mr. Herriot.” I heard his voice. I turned a blank gaze on him — I just had no idea    小题7:  he was though his face was familiar. Then I saw 小题8:__     word “MEAD” in foot­high letters above the shop window.

“Good morning, Mead,” I cried heartily and continued my way. I had gone only a few steps before I realized that my greeting had been  小题9: (polite). I turned back and said to him again, “Good morning, Mister Mead.”

It was only when I has turned the corner of the street that I realized, too late,    小题10:   his name was Tony and the time was late afternoon.

多项选择题