问题 选择题

有X、Y、Z、W、M五种短周期元素,其中X、Y、Z、W同周期,Z、M同主族;X+与M2具有相同的电子层结构,离子半径:Z2->W;Y的内层电子总数是最外层电子数的5倍。下列说法中不正确的是  (   )

A.W、M的某种单质可作为水处理中的消毒剂

B.电解YW2的熔融物可制得Y和W的单质

C.相同条件下,w的氢化物水溶液酸性比Z弱

D.X、M两种元素形成的一种化合物与水反应可生成M的某种单质

答案

答案:C

题目分析:Y的内层电子数是外层电子数的5倍,可得Y的内层电子总数为10,最外层电子数为2,故为镁;X+与M2具有相同的电子层结构,故为钠和氧,由Z、M同主族可得Z为硫,根据离子半径Z2->W得W为氯;A、单质臭氧和氯气均能用于水的消毒剂,故A正确;B、电解熔融的氯化镁可制得镁和氯气单质,B正确;W的氢化物为HCl,Z的氢化物为H2S,酸性HCl>H2S,C错误;钠和氧构成的化合物过氧化钠和水反应生成氧气,D正确;故选C。

阅读理解

Life in the future will be different from life today. Between then and now many changes (改变)will happen. But what will the changes be?

The population (人口) is growing fast. There will be many people in the world and most of them will live longer than people live now.

Computers will be much smaller and more useful, and there will be at least (至少) one in every room. And computer studies will be one of the important subjects in schools then. People will work fewer hours than they do now and they will have more free time for sports, watching TV and travel. Traveling will be much cheaper and easier. And many more people will go to other countries for holidays.

There will be changes in our food, too. More land will be used for building new towns and houses for all the people. Then there will be less room for cows and sheep, so meat will be more expensive. Maybe no one will eat it every day. Instead they will eat more fruit and vegetables. Maybe people will be healthier. Work in the future will be different, too. Robots will do dangerous and hard work. Because of this, many people will not have enough work to do. This will be a problem.

小题1:In the future there will be _______.

A. much more fruit   B. more people     C. less vegetables

小题2:Every family will have at least a _____________ in the future.

A. robot            B. cow           C. computer

小题3:In the future people don’t have to __________________

A. work long hours   B. work fast      C. walk on foot

小题4:People may not eat _________ as much as they do today.

A. fruit             B. fish           C. meat

小题5:One big problem in the future is that ___________.

A. many people will not be able to find work

B. people have to work fast

C. all the work will be done by robots

选择题