问题 填空题

(6分)在宏观,微观和符号之间建立联系是化学学习的特点。

(1)用化学用语填空:

①一个镁离子        ;            ②-2价的氧元素         

③地壳中最多的金属元素和非金属元素组成的化合物        

(2)自来水消毒过程中常会发生如下化学反应,其反应的微观过程可用下图表示:

①图乙所示反应的基本类型为      

②物质D中氯元素的质量分数     

③写出图甲所示反应的化学方程式                           

答案

(1) ①Mg2+        ③Al2O3

(2) ①分解  ②67.6% ③H2O+Cl2=HCl+HClO

(1)用化学用语填空:

①一个镁离子:由于镁离子是带两个单位正电荷的,所以应该是在Mg的右上方标注,数字在前,正号在后.即 Mg2+;②-2价的氧元素:元素的化合价应该表在元素的正上方,所以-2价的氧元素为

③地壳中含量最多的金属元素和非金属元素分别为Al、O,其化合价分别为+3价、-2价,根据化合价的代数和为零,所以应该是原子个数2:3,正价在前负价在后,其化学式为Al2O3

(2)图甲的反应为H2O+Cl2=HCl+HClO,图乙的反应为2HClO=2HCl+O2

①从方程式很容易看出,乙反应是一种物质生成两种产物,所以为分解反应;

②D为HClO,其中氯元素的质量分数为

③图甲的反应为H2O+Cl2=HCl+HClO.

故答案:(1)①Mg2+;②;③Al2O3.(2)①分解;②67.6%;③H2O+Cl2=HCl+HClO.

阅读理解

Mr. Ma, a famous mental doctor from Beijing once said at an important meeting, “Now many young students can have problems with their minds. Some students become worried because they have to study very hard. Others have trouble getting on well with people around them like their parents and classmates. Parents and teachers should care more about this problem.”

Then Mr. Ma gave some examples. One patient, a middle school student from Xi’an, was doing  badly in his lessons. He thought his teachers and friends often laughed at him, and he became so nervous and worried that one night he left his home without telling his parents. Another student, a 14-year-old school girl form Shanghai, was very afraid of exams. While she was reading the exam paper, she couldn’t think of anything to write.

A recent report from Jiefang Daily says about 18% of young students in Shanghai have mental problems. They often feel worried and very unhappy. Unluckily many of them won’t go and ask for help. Some think they will look stupid if they go to see a doctor. Others won’t talk about their secrets.

At the end of the meeting, Mr. Ma offered some good ideas to young people:

●Talk to your parents ore teachers often.

●Take part in group activities.

●Try to get on well with the people around you.

●Go to see a doctor if you often feel unhappy.

小题1:The students who often become worried or have trouble getting on with others may have ______

A. no parents         B. poor memories            C. mental problems

小题2:The school girl’s problem happened whenever she ________

A. studied very hard    B. had exams               C. talked with her parents

小题3:Some of those with metal problems won’t ask for help because _____

A. they don’t’ want to tell their secrets to others 

B. their parents are too busy to look after them.

C. doctors can’t help them with the problem

小题4:The underlined word “stupid” in this passage means ______

A. studying         B. happy                C. not clever

小题5:According to the last part, which of the following is a good idea?

A. It’s important for children to live with their parents.

B. It’s useful for students to keep quiet in class.

C. It’s not necessary for young people to have more group activities.

单项选择题