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Which one of the following statements is correct?

Options

  1. AA neutron is formed by combination of an electron and a proton. Therefore, it is neutral
  2. BThe mass of an electron is about 1/2000 times that of a proton
  3. CAn isotope of cobalt is used in the treatment of goiter
  4. DJ. J. Thomson proposed that the nucleus of an atom contains only neutrons

Correct answer

B. The mass of an electron is about 1/2000 times that of a proton

Step-by-step solution

Statement 1 is incorrect because a neutron is a fundamental subatomic particle, not a combination of an electron and a proton. Statement 2 is correct because the mass of an electron is approximately 1 1837 times the mass of a proton, which is roughly 1 2000 . Statement 3 is incorrect because an isotope of iodine (I-131) is used in the treatment of goiter, whereas an isotope of cobalt (Co-60) is used in the treatment of cancer. Statement 4 is incorrect because J. J. Thomson proposed the plum pudding model of the ato

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