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问题 填空题

有A、B、C、D四种短周期主族元素，它们的原子序数依次增大，其中A元素原子核外电子仅有一种原子轨道，也是宇宙中最丰富的元素，B元素原子核外p电子数比s电子数少1，C为金属元素且原子核外p电子数和s电子数相等，D元素的原子核外所有p轨道全充满或半充满。

（1）写出四种元素的元素符号：

A________，B________，C________，D________。

（2）写出C、D两种元素基态原子核外电子轨道表示式。

C_______________________________________________________________，

D_______________________________________________________________。

（3）写出B、C两种元素单质在一定条件下反应的化学方程式____________________________________________。

（4）写出B元素单质和氢化物的电子式：单质________，氢化物__________。

答案

（1）H　N　Mg　P

（2）

A是宇宙中最丰富的元素，则A为氢；B元素原子的核外电子排布为

1s22s22p3，为氮；C元素原子的核外电子排布为1s22s22p63s2，为镁；D元素

原子的核外电子排布为1s22s22p63s23p3，为磷。

单项选择题

烤烟在醇化过程中，氨基酸均呈（）的趋势。

A.增加

B.减少

C.不变

D.以上都有可能
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     In the depths of my memory , many things  I  did with my father still live. These things have come to
represent,in fact, what I call   1    and love.
      I don't remember my father ever getting into a swimming pool.
But he did    2    the water. Any kind of   3   ride seemed to give him pleasure.   4   he loved to fish;
sometimes he took me along.
      But I never really liked being on the water, the way my father did. I liked being    5     the water,
moving through it,    6     it all around me. I was not a strong    7   , or one who learned to swim early,
for I had my    8   . But I loved being in the swimming pool close to my father's office and     9     those
summer days with my father,who 10  come by on a break. I needed him to see what I could do. My
father would stand there in his suit,the 11 person
not in swimsuit.
     After swimming,l would go   12  his office and sit on the wooden chair in front of his big desk, where
he let me   13   anything I found in his top desk drawer. Sometimes, if I was left
alone at his desk   14   he worked in the lab, an assistant or a student might come in and tell me perhaps
I shouldn't be playing with his   15  . But my father always   16  and said easily,"Oh,
no,it's 17 . " Sometimes he handed me coins and told me to get   18   an ice cream…
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( )18. A. the student  
( )19. A. memory      
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B. refuse          
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B. Then            
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B. break down      
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B. who             		C. anger          
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C. what           		D. worry              
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