A radioactive decay can form an isotope of the original nucleus with the emission of particles

Options

A. one `alpha` and four `beta`
B. one `alpha` and two `beta`
C. one `alpha` and one `beta`
D. four `alpha` and one `beta`

Answer

B

Explanation

Emission of `alpha-` particle decreases the atomic number and the mass number by 2 and 4 respectively. Emission of `beta-` particle increases the atomic number by 1 while the mass number remains unchanged. Therefore, after the emission of one `alpha` and two `beta-` particles, the atomic number remains the same while the mass number decreases by 4. Hence, the emitted nucleus is the isotope of hte original nucleus.