搜题请搜索小程序“爱下问搜题”
问题 填空题

（7分）（1）X原子在第二电子层上只有一个空轨道，其电子排布式为              ；R原子的3p轨道上只有一个未成对电子，则R原子可能是              、              ；

（2）Y原子的核电荷数为29，元素符号为              ，其价电子构型是              ，该元素在元素周期表中的位置是              ，是属于       区的元素。

答案

（7分）1S22S2P2；Al，Cl；  Cu    3d104s1，第四周期ⅠB，ds区。（各1分）

（1）X原子在第二电子层上只有一个空轨道，则X是碳元素，电子排布式为）1S22S2P2；R原子的3p轨道上只有一个未成对电子，则R可以是13号元素铝或17号元素氯。

（2）原子序数为29的是铜，元素符号为Cu。根据构造原理可知，价电子构型是3d104s1，位于第四正确第ⅠB。区的名称来自按照构造原理最后填入电子的能级符号，所以铜属于ds区元素。

阅读理解

As young students, you have many dreams. These dreams can be very big, such as winning the Noble Prize; they can also be small, such as becoming one of the best students in your class. Once you find a dream, what do you do with it?  小题1:

Andrew Matthews, an Australian writer, tells us that making your dreams real is life’s biggest challenge. You may think you’re not very good at some school subjects, or that it’s impossible for you to become a writer.  小题2:

 小题3: The first thing you must do is to remember what your dream is. Don’t let it leave your heart. Keep telling yourself what you want every day and then your dream will come true faster. You should know that a big dream is, in fact, made up of many small dreams.

 小题4:There will be difficulties on the road to your dream. But the biggest difficulty comes from yourself.    小题5: Studying instead of watching TV will help you get better exam results, while saving five yuan instead of buying an ice cream means you can buy a new book.

As you get closer to your dream, it may change a little. This is good as you have the chance to learn something more useful and find new hobbies.

从方框中所给的选项中选出能填入空白处的最佳选项，补全短文。其中有一项为多余

选项。(10分)
查看答案
单项选择题 A1型题

重症肌无力的主要临床特征为

A．全身骨骼肌均可无力

B．颅神经支配肌肉的无力多于脊神经支配的肌肉

C．受累骨骼肌的极易疲劳性和短时休息后好转

D．病情波动

E．感染后肌无力加重
查看答案