问题 选择题

下列有关化学用语正确的是   (  )                 

A.某元素原子的轨道排布式

B.NH3电子式为

C.Ca2+离子基态电子排布式为1s22s22p63s23p6

D.钾(K)原子的原子结构示意图为

答案

答案:C

氧元素基态原子的轨道排布式应为:[He]然后表示出2S层的两个电子和2P层的4个电子,故A错误;

氮原子最外层应达8电子稳定结构,故B错误;

钾(K)原子核外电子排布应为2 8 8 1,故D错误

填空题
阅读理解

 In a great many cities, hundreds of people ride bicycles to work everyday. In New City, some bike riders have even formed a group called Bike for a Better City. They declare that if more people rode bicycles to work, there would be fewer automobiles(汽车) in the downtown part of the city and so less dirty air from car engines. For several years this group has been trying to get the city government to help bicycle riders. For example. They want the city to draw special lanes(通道) for bicycles only on some of the main streets, because when bicycle riders must use the same lanes as cars, there are accidents. Bike for a Better city feels that if there were special lanes more people would use bikes.

But no bicycles lanes have been drawn. Not everyone thinks they are a good idea-----they say it will slow traffic. Some store owners on the main streets don't like the idea------they say that if there is less traffic, they will have less business.

The city government has not yet decided what to do. It wants to keep everyone happy. On weekends, Central Park----the largest place of open ground in New York----is closed to cars, and the roads may be used by bicycles only. But Bike for a Better City says that this is not enough and keeps fighting to get bicycle lanes downtown.

73. The bike riders suggest that _____________.

A. bicycles should be used instead of cars    B. bicycle lanes should be drawn

C. fewer buses or cars should be used  D. the number of special lanes should be increased

74. The advantage(好处) of the special lanes is that _______.

A. they will make cars and buses run slowly   B. they will make it easier for bike riders to go to parks

C .they will make the city more beautiful    D. the lanes will prevent accidents

75. The government has not decided whether special lanes should be drawn ______.

A. so that everyone is disappointed      B. because there are different opinions

C. because most people travel by train   D. because Bike for a Better City is not strong enough