Question

During \( \alpha \)-decay, the atomic mass of parent nuclei is

Hint:

In \( \alpha \)-decay, the mass number of the parent nucleus decreases by 4 units due to the emission of an alpha particle.

Answer 1

During \( \alpha \)-decay, an alpha particle, which consists of 2 protons and 2 neutrons, is emitted from the parent nucleus. As a result, the atomic number of the parent nucleus decreases by 2, and the atomic mass decreases by 4. Therefore, the correct answer is (C).