Nguyên tố Bo có 2 đồng vị $11B$ ( $x_1$ %) và $10B$ ( $x_2$ %), nguyên tử khối trung bình của Bo là 10,8. Giá trị của $x_1$ % là:

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Một số câu hỏi khác có thể bạn quan tâm.

• Find a mistake in the four underlined parts of the sentence and correct it:

  Absolutely nothing that floats, neither a corked bottle nor a 50,000-ton ships can escape the effects of water currents.

• Find a mistake in the four underlined parts of the sentence and correct it:

  The president was made resign by the rebels.

• Find a mistake in the four underlined parts of the sentence and correct it:

  It is believed that there is another world for the death people.

• Find a mistake in the four underlined parts of the sentence and correct it:

  It’s him who has won the gold medal for men’s long jump.

• Choose one sentence that has the same meaning as the root one:

  Tom is good at English. He is good at French, too.
  
  

• Choose one sentence that has the same meaning as the root one:

  People think Mrs. Nga is a good step mother.
  
  

• Choose one sentence that has the same meaning as the root one:

  It is said that Tom married a girl whose father is a millionaire two years ago.
  
  

• Choose one sentence that has the same meaning as the root one:

  People say a water park is going to be built in our area.
  
  

• Choose one sentence that has the same meaning as the root one:

  The car was heavy but he managed to lift it.
  
  

• Choose one sentence that has the same meaning as the root one:

  He is honest so she loves him.