Question

Which of the following is not a mode of radioactive decay?
A. Positron emission
B. Electron capture
C. Fusion
D. Alpha decay

Answer 1

Hint:When the nucleus becomes unstable due to too many protons and neutrons, radioactive decay occurs. Particles released from the decaying nucleus stabilize the nucleus. Whereas in fusion light nuclei combine to form the heavy nucleus and a large amount of energy is released.

Complete step by step solution:
A substance that has unstable nuclei is regarded as radioactive. Alpha decay, beta decay, and gamma decay are three of the most frequent kinds of decay, and they all entail the emission of one or more particles. Beta decay is a result of the weak force, while the nuclear force and electromagnetism are in charge of the other two mechanisms.

Electron capture, which occurs when an unstable nucleus seizes an inner electron from one of the electron shells, is the fourth prevalent kind of decay. Discrete X-rays are released from the transitions as a result of the loss of that electron from the shell, which causes a cascade of other electrons to fall into the lower shell. Iodine-125, which is frequently utilized in medical contexts, is an example.

Nuclear fusion is the process by which two light nuclei merge (at a very high temperature) to create a single heavy nucleus. The mass of the single nucleus that results from this process is less than the total mass of the parent nuclei. A tremendous amount of energy is produced as a result of this mass difference. A fusion process does not produce radioactive decay products like alpha, beta, or gamma rays, hence it is not a radioactive decay.

Hence, the correct answer is option C.

Note: A rapidly energetic electron or positron, known as a beta particle, is released from an atomic nucleus during the radioactive decay process known as beta decay. A radioactive process known as "alpha decay" occurs when an atomic nucleus produces an alpha particle, changing into a new atomic nucleus with a mass number that is reduced by 4 and an atomic number that is reduced by 2.