问题 推断题

A、B、C、D、E五种短周期元素,原子序数依次增大,其中只有C为金属元素。A、C原子序数之和等于E的原子序数,D与B同主族且D原子序数是B原子序数的2倍。AB2和DB2溶于水得到酸性溶液,C2D溶于水得到碱性溶液。

(1)E元素在周期表中的位置为___________;工业上制取C 单质的化学方程式为_____________________。

(2)A的最低负价氢化物的空间构型为________;C、D、E 的简单离子的离子半径由大到小的顺序是

________________(用离子符号表示)。

(3)在低温下,将E的单质通入饱和NaHCO3溶液中,反应后得到一种微绿色气体E2B、CE和另外一种无色气体。则该反应中E2B、CE这两种产物的物质的量之比n(E2B):n(CE)=____。已知E2B溶于水生成一种具有漂白性的弱酸,该弱酸分子的结构式为________。

(4)化合物C2D3中,各原子(或离子)最外层均达到8电子稳定结构,则C2D3的电子式为________,该化合物的水溶液在空气中久置后变质,生成一种单质,所得溶液呈强碱性,用化学方程式表示这一变化过程____________________

答案

(1)第三周期ⅦA族;

(2)正四面体形;S2- >Cl- >Na+

(3)1:2;H-O-Cl

(4);2Na2S3 + O2 + 2H2O=4NaOH + 6S↓

阅读理解

C    

My name is A. J. Hoge. I am the creator of the Effortless English Teaching System and I am the Founder and Director of The Effortless English Club——one of the most popular English learning systems in the world. My audio lessons are best-sellers in over 25 countries and my radio podcast (播客)has over one million listeners worldwide. I am also the publisher of the Effortless English Online Newsletter, which has over half a million subscribers(用户) (and growing every day). I am a leading expert on topics related to English speaking success and teaching mastery.

I created the Effortless English Teaching System after many years of teaching English in universities. My former students include business professionals, scientists, teachers, professors, graduate students, and many other successful adult English learners. These students were just like you. They were frustrated English learners who could not speak well. Using the Effortless English system, they learned to speak English easily and automatically.

Each of these students made incredible improvements in a very short time. You also will improve quickly when you use the entire Effortless English System. The Effortless English System is designed for you——the independent adult learner. Effortless English focuses exclusively on speaking and listening skills. The system is designed to improve your speaking power as quickly as possible——using proven and tested methods.

When you follow the entire system every day for 6 months, your speaking becomes much faster and easier. Your spoken grammar improves powerfully——yet you will never study grammar rules in this system. Your pronunciation improves powerfully——yet you will not focus on pronunciation.

49.What's the author's purpose of writing this text?

A.To introduce himself.

B.To suggest some ways of speaking English easily and automatically.

C.To show readers he is a successful English teacher.

D.To make his Effortless English System popular.

50.The text is intended for____.

A.the students whose English is poor

B.the learners whose English pronunciation and grammar are not good

C.the adults who plan to make their English speaking ability improved

D.the English teachers who want to their improve English teaching techniques

51.The author's Effortless English System doesn't deal with      .

A.how to learn English grammar and pronunciation

B.advanced teaching methods

C.English speaking skills

D.English listening skills

52.What will the author discuss in the following text?

A.What he did when he was an English teacher.

B.The Effortless English System overview.

C.His radio podcast.

D.The Effortless English Club.

选择题