Ion Y2+ có cấu hình electron:. Vị trí của Y trong bảng tuần hoàn là: 

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Một số câu hỏi khác có thể bạn quan tâm.

• Đặc điểm chung của Liên Minh Châu Âu và Hiệp hội các nước Đông Nam Á là
  

• Treo một vật khối lượng 100 g vào lò xo có độ cứng k thì lò xo dãn ra 1 cm. Khi treo vật có khối lượng 300 g vào lò xo thì nó dãn: 

• Read the passage and choose the correct answer:
  Galileo Galilei, one of the first modern scientists, was born in Pisa, Italy, in 1564. About twenty years later he attended the University of Pisa. At first he studied philosophy, but later he studied mathematics and astronomy. He was interested in the way the earth and other planets move around the sun. He made the telescope, which made far-away things look larger and easier to examine. He also started the new way of working in science. Before Galileo; scientists did not do experiments. They just guessed about how something happened. Galileo was different. He did not just make guesses. He did experiments and watched to see what happened.
  Galileo was famous for his study of how things fall. He was the first person to do experiments about this problem. Before, people thought that heavy things always fell faster than light things. He found out that this was not true. He took a heavy ball and a light ball and he dropped them both from a high place. They fell at the same speed. This meant that weight is not important. This is the law of failing bodies. It is an important law for understanding our world.
  The life of the scientist was not always easy in the 1500s. For example, Galileo got into trouble because of his scientific ideas. His ideas were not the same as the religious ideas at the time. Many religious people did not agree with him. During his whole life he had to worry about this. He even went to prison for a while. But no one could stop him from thinking: He continued to look for scientific answers to his questions about the world.
  Question. Which of the following is not true about Galileo?. . . . . . . . . . . . . .
  

• If I were in your place, I ________a trip to England.

• Có bao nhiêu giá trị nguyên của tham số thuộc đoạn để phương trình có nghiệm.                                 

• Sóng ngang là sóng

• Cho hàm số . Tìm a để hàm số đạt cực đại tại .         

• I would rather that I _______Bill Gate so I could give money to the poor.

• Lai phân tích cơ thể có 2 cặp gen thu được 4 kiểu hình với tỉ lệ 1:1:1:1. Kiểu gen của cơ thể đem lai phân tích có thể như thế nào?

  (1) AaBb.                                         (2) hoặc (với f =25%)

  (3) hoặc  (với f =50%).                 (4) hoặc  (liên kết hoàn toàn).         

• Hình thành thị trường chung châu Âu đã tác động như thế nào đến các hãng vận tải hoạt động ở khu vực này?