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JAMB Physics 1991 Question 49

Question 49

Radioactivity and Nuclear Physics

Which of the following are TRUE for α-decay? I. Mass number decreases by four II. Atomic number decreases by two III. Mass number does not change

  1. A.I and II only
  2. B.II and III only
  3. C.I and III only
  4. D.I, II and III.
Show the answer and explanation

Answer: A (I and II only)

Explanation

An alpha particle is 42He, so the nucleus loses 4 from its mass number and 2 from its atomic number.