Question

A radioactive element forms its own isotope after 3
consecutive disintegrations. The particles emitted are
(a) 3 β–particles
(b) 2 β–particles and 1 α–particle
(c) 3 β–particles and 1 α–particle
(d) 2 α–particles and 1 β–particle.

Answer 1

Answer:

B) 2 β particles and 1 α particle

Explanation:

2β particles cause rise of mass number by 2 and atomic number by 2. Then 1α particle causes decrease in mass number by 4 and atomic number by 2. As a result, the new atom will have atomic number same as before but different mass number. That is the new atom will be an isotope of the original atom.