题干

据科学家预测,月球的土壤中吸附着百万吨的氦(He﹣3),其原子核中质子数为2、中子数为1,每百吨氦(He﹣3)核聚变所释放出的能量相当于目前人类一年消耗的能量.下列关于氦(He﹣3)元素的说法正确的是(  )


A:原子核外电子数为3  

B:相对原子质量为2

C:原子结构示原子结构示意图为

D:原子结构示意图为

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答案(点此获取答案解析)

D

同类题5

请认真阅读下面短文,并根据短文内容回答问题。
Dear Helen,
      Thanks for your last letter. Yes, I'm enjoying myself on my exchange program in France. It's even better than I thought it would be. I was a bit nervous before I arrived here, but there was no reason to be. My host family are really nice. They go out of their way to make me feel at home. And you wouldn't believe how quickly my French has improved! I'm very comfortable speaking French now. Although I still make lots of mistakes, it doesn't make me worried as it used to. My biggest challenge (挑战) is learning how to behave (表现) at the dinner table. As you can imagine, things are really not the same as the way they are at home. For example, you shouldn't put your bread on your plate. You should put it on the table! I thought that was very strange at first, but now I'm used to it. You shouldn't eat anything with your hands except bread, not even fruit! (You have to cut it up and eat it with a fork.) Another thing is that it is very rude to say you're full. If you don't want any more food, you should just say, “It was delicious.” Also, it's rude to put your hands in your lap. You should always keep your hands, but not your elbows (肘部), on the table. I have to say, I find it difficult to remember everything, but I'm gradually getting used to things and don't find them so strange any more.
      I'll write soon and tell you more about life in France. Hope you're having a good school year.
Yours,
Li Ying