题干

 如图为元素周期表中铈元素的信息,下列有关说法错误的是(  )

A:铈原子核内中子数为58  

B:铈原子核外电子数为58

C:铈的相对原子质量为140.1

D:铈的原子序数为58

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答案(点此获取答案解析)

A

同类题3

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    During all this time I never stopped thinking about escape. When I traveled across to the other side of the island, I could see the other islands, and I said to myself, "Perhaps I can get there with a boat. Perhaps I can get back to England one day."

    So I decided to make myself a boat. I cut down a big tree, and then began to make a long hole in it. It was hard work, but about six months later, I had a very fine canoe (独木舟). Next, I had to get it down to the sea. How silly I was! Why didn't I think before I began work? Of course, the canoe was too heavy. I couldn't move it! I pulled and pushed and tried everything, but it didn't move. I was very unhappy for a long time after that.

    That happened in my fourth year on the island. In my sixth year I did make myself a smaller canoe, but I did not try to escape in it. The boat was too small for a long journey, and I did not want to die at sea. The island was my home now, not my prison, and I was just happy to be alive. A year or two later, I made myself a second canoe on the other side of the island. I also built myself a second house there, and so I had two homes.

    My life was still busy from morning to night. There were always things to do or to make. I learnt to make new clothes for myself from the skins of dead animals. They looked very strange, it is true, but they kept me dry in the rain.

    I kept food and tools at both my houses, and also wild goats. There were many goats on the island, and I made fields with high fences to keep them in. They learnt to take food from me, and soon I had goats' milk to drink every day. I also worked hard in my corn (玉米) fields. And so many years went by.