Question

choose the statement about nuclear fusion that is always correct?
a very little energy is released in fusion processes.
b due to its instability, 56fe readily undergoes fusion.
c nuclear fusion is an energetically favorable process for lighter atoms.
d in fusion reactions, a proton and an electron combine to create a neutron.

Explanation:

• Option A: Nuclear fusion releases a large amount of energy, not very little. For example, the energy from the sun is generated by nuclear fusion. So, this option is incorrect.
• Option B: \(^{56}\text{Fe}\) is a very stable nucleus. It does not readily undergo fusion. In fact, in stars, when iron is formed in the core, it marks the end of the star's normal fusion - based energy - generation process. So, this option is incorrect.
• Option C: Nuclear fusion is energetically favorable for lighter atoms. Lighter nuclei (such as hydrogen isotopes) have a relatively large mass per nucleon compared to the nuclei formed after fusion (e.g., helium). According to Einstein's \(E = mc^{2}\), the mass difference is converted into energy, and this process releases energy. This is a fundamental property of nuclear fusion for lighter elements.
• Option D: The process of a proton and an electron combining to create a neutron is electron - capture (a type of radioactive decay), not a fusion reaction. Fusion reactions involve the combination of light nuclei (e.g., \(^{2}\text{H}+^{3}\text{H}\to^{4}\text{He}+n\)). So, this option is incorrect.

Answer:

C. Nuclear fusion is an energetically favorable process for lighter atoms.