问题 选择题

关于物质结构的叙述正确的是

A.所有的物质中都存在化学键

B.原子的次外层电子数都是8

C.稀有气体原子的最外层电子数均为8

D.原子的最外层电子数不超过8

答案

答案:D

题目分析:稀有气体分子中不存在化学键,A不正确;第二正确元素的次外层电子数都是2个,B不正确;C不正确,He的最外层电子数是2个;根据核外电子排布规律可知,原子的最外层电子数不超过8个,D正确,答案选D。

点评:该题是中等难度的试题,试题基础性强,在注重对学生基础知识巩固和检验的同时,侧重对学生能力的培养。该题的关键是学会通过举例逐一排除筛选得出正确结论的方法,有利于调动学生的学习兴趣,提高学生的应试能力。

完形填空
完形填空。
     Feifei and her brother are students. They are in the same school. Feifei gets up at five past six. But her brother
doesn't get up    1   . So he always has    2       breakfast and comes to school late. Feifei and her brother go to school
   3   bike. Feifei gets to school at half past seven. Classes    4   at quarter past eight. They have    5   at school. In the
afternoon, they have three lessons.   They go    6   at half past four.   And    7   their way home,   Feifei's brother    8  
plays in the street (街道).   But Feifei has to    9   some food for their dinner.   At home,   Feifei's mother cooks(烹饪)
dinner. Her father is a teacher, and he has    10    classes at school till(直到) nine o'clock.
( )1. A. late     
( )2. A. no       
( )3. A. on          
( )4. A. begins      
( )5. A. lunch       
( )6. A. to school    
( )7. A. on          
( )8. A. never(从不)  
( )9. A. eat        
( )10.A. evening     
B. early     
B. nice     
B. in          
B. begin        
B. breakfast   
B. home       
B. in          
B. seldom(很少)
B. buy         
B. morning  
C. later        
C. good        
C. by          
C. are          
C. supper      
C. out          
C. to          
C. usually      
C. cook        
C. afternoon    
单项选择题 A1/A2型题