Which of the following is the overall fusion reaction by which the Sun currently produces energy?

• A. 2\,^{2}\!\mathrm{H} \rightarrow \, ^{4}\!\mathrm{He} + \text{energy}
• B. 4\,^{1}\!\mathrm{H} \rightarrow \, ^{4}\!\mathrm{He} + 2\,e^{+} + 2\,\nu_{e} + \text{energy}
• C. ^{12}\!\mathrm{C} + ^{16}\!\mathrm{O} \rightarrow ^{28}\!\mathrm{Si} + \text{energy}
• D. ^{14}\!\mathrm{N} + ^{1}\!\mathrm{H} \rightarrow ^{15}\!\mathrm{O} + \gamma

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the context of the problem. The question is asking about the primary fusion reaction that occurs in the Sun to produce energy. This involves nuclear fusion, where lighter nuclei combine to form heavier nuclei, releasing energy in the process.
2. Step 2: Recall the main fusion process in the Sun. The Sun primarily produces energy through the proton-proton chain reaction, which involves the fusion of hydrogen nuclei (protons) to form helium nuclei, positrons, neutrinos, and energy.
3. Step 3: Analyze the given options. The correct answer should match the proton-proton chain reaction, which can be summarized as: \( 4\,^{1}\!\mathrm{H} \rightarrow \, ^{4}\!\mathrm{He} + 2\,e^{+} + 2\,\nu_{e} + \text{energy} \). This reaction represents the fusion of four hydrogen nuclei into one helium nucleus, accompanied by the release of positrons, neutrinos, and energy.
4. Step 4: Eliminate incorrect options. For example, \( 2\,^{2}\!\mathrm{H} \rightarrow \, ^{4}\!\mathrm{He} + \text{energy} \) is not the primary reaction in the Sun, and \( ^{12}\!\mathrm{C} + ^{16}\!\mathrm{O} \rightarrow ^{28}\!\mathrm{Si} + \text{energy} \) describes a process that occurs in more massive stars during later stages of their life cycle.
5. Step 5: Confirm the correct answer. The correct reaction is \( 4\,^{1}\!\mathrm{H} \rightarrow \, ^{4}\!\mathrm{He} + 2\,e^{+} + 2\,\nu_{e} + \text{energy} \), which aligns with the proton-proton chain reaction responsible for the Sun's energy production.