Question

Q. With reference to radioactive decay, consider the following statements:

Which of the statements given above is/are correct?

• A.
  1 only
• B.
  1 and 3 only
• C.
  2 and 3 only
• D.
  1,2 and 3

Answer 1

The correct option is C

2 and 3 only

Explanation:

Statement 1 is incorrect: Alpha decay is decay in which the Helium nucleus is emitted, not electrons or positrons.

Statement 2 is correct: In beta decay and nucleus spontaneously emits an electron or a

positron. In beta decay, the mass number remains unchanged.

Statement 3 is correct: When a nucleus in an excited state spontaneously decays into the ground state, a photon is emitted with energy equal to the difference in the two energy levels of the nucleus.