What energy process powers the Sun?

What energy process powers the Sun?

• A. Nuclear fission in the Sun's core
• B. Radiation from external energy sources
• C. Gravitational contraction
• D. Nuclear fusion in the Sun's core

Answer: (D)

Hydrogen fusion powers the Sun. In the hot, dense core, hydrogen nuclei fuse to form helium through the proton–proton chain. This fusion releases energy because the resulting helium has slightly less mass than the four hydrogen nuclei did, and that mass difference becomes energy carried away as photons and neutrinos. That energy travels outward by radiation and convection and emerges as the sunlight we receive. Gravitational contraction can power a star only during formation or contraction phases, not as the ongoing source for a mature Sun, and nuclear fission isn’t how stars produce energy.

Hydrogen fusion powers the Sun. In the hot, dense core, hydrogen nuclei fuse to form helium through the proton–proton chain. This fusion releases energy because the resulting helium has slightly less mass than the four hydrogen nuclei did, and that mass difference becomes energy carried away as photons and neutrinos. That energy travels outward by radiation and convection and emerges as the sunlight we receive. Gravitational contraction can power a star only during formation or contraction phases, not as the ongoing source for a mature Sun, and nuclear fission isn’t how stars produce energy.