Which process in the Sun produces energy by fusing hydrogen into helium?

Which process in the Sun produces energy by fusing hydrogen into helium?

• A. Nuclear fission
• B. Radioactive decay
• C. Nuclear fusion
• D. Chemical reaction

Answer: (C)

The Sun’s energy comes from nuclear fusion, where light nuclei join to form heavier ones. In the solar core, hydrogen protons fuse through processes like the proton–proton chain to make helium, converting a small amount of mass into energy that propagates outward as sunlight and heat. This fusion requires the extreme temperatures and pressures found in the Sun, which allow protons to overcome their electrical repulsion and stick together. Nuclear fission, by contrast, would split heavy nuclei into lighter pieces to release energy, which is not what powers the Sun. Radioactive decay involves unstable nuclei breaking down over time, releasing radiation, but it’s not the ongoing energy source for the Sun on the scale we observe. Chemical reactions involve rearranging electrons and bonds and release far less energy, with no change to the atomic nucleus, so they do not account for the Sun’s sustained energy output. Therefore, the energy-producing process in the Sun is nuclear fusion.

The Sun’s energy comes from nuclear fusion, where light nuclei join to form heavier ones. In the solar core, hydrogen protons fuse through processes like the proton–proton chain to make helium, converting a small amount of mass into energy that propagates outward as sunlight and heat. This fusion requires the extreme temperatures and pressures found in the Sun, which allow protons to overcome their electrical repulsion and stick together.

Nuclear fission, by contrast, would split heavy nuclei into lighter pieces to release energy, which is not what powers the Sun. Radioactive decay involves unstable nuclei breaking down over time, releasing radiation, but it’s not the ongoing energy source for the Sun on the scale we observe. Chemical reactions involve rearranging electrons and bonds and release far less energy, with no change to the atomic nucleus, so they do not account for the Sun’s sustained energy output. Therefore, the energy-producing process in the Sun is nuclear fusion.