A元素原子M电子层上有6个电子．B元素与A元素的原子核外电子层数

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问题问答题

A元素原子M电子层上有6个电子．B元素与A元素的原子核外电子层数相同，B元素的原子最外电子层只有1个电子．

（1）B元素的原子结构示意图为______．

（2）A、B两元素形成的化合物的名称是______，化学式是______，该化合物在无色火焰上灼烧时，火焰呈______色．

答案

A元素原子M电子层上有6个电子，核外电子排布为2、8、6，则原子序数为16，应为S元素，B元素与A元素的原子核外电子层数相同，应为第三周期元素，B元素的原子最外电子层只有1个电子，应为第ⅠA族元素，则B为Na元素，

（1）B为Na元素，原子核外有3个电子层，最外层电子数为1，则原子结构示意图为

，故答案为：

；

（2）A为S元素，B为Na元素，二者形成的化合物为Na₂S，，名称为硫化钠，Na元素的焰色反应为黄色，

故答案为：硫化钠；Na₂S；黄．

完形填空

Last Friday, after doing all the family shopping in the town, I wanted to have a rest before catching the train. I ____ a newspaper and some chocolate and ____ into the station coffee shop. It was a cheap self-service place with long tables to ____ at. I put my heavy bag down on the floor, ____ the newspaper and the chocolate on the table and then went to get a cup of coffee.
When I came back with the coffee, There was someone ____ in the next seat. ____ was a boy, with dark glasses and old clothes, and ____ bright red at the front. He had started to eat my chocolate!
Naturally, I was rather uneasy about him, but I didn’t want to have any ____. I just read the newspaper, tasted my coffee and took a bit of chocolate. The boy looked at me in ____.Then he took a ____ piece of my chocolate. I could hardly believe it. Still I didn’t say anything to him. When he took a third piece, I felt more angry than uneasy. I thought, “Well, I shall have the last piece.” And I got it.
The boy gave me a strange look, then ____ up. As he left, he shouted out, “There’s something ____ with that woman!” Everyone looked at me, ____ I didn’t want to quarrel with the boy, so I kept quiet. I did not realize that I had ____ a mistake until I finished my coffee and was ready to ____. My face turned red when I saw my unopened chocolate under the newspaper. The chocolate that I had been eating was the boy’s!

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填空题

存在职业病危害的用人单位，应当委托具有相应资质的职业卫生技术服务机构，每年至少进行（）职业病危害因素检测；职业病危害严重的用人单位，除遵守前款规定外，应当委托具有相应资质的职业卫生技术服务机构，每三年至少进行一次职业病危害现状评价。

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