Which zone surrounds the Sun's core where energy moves from atom to atom?

• A. Convection Zone
• B. Radiative zone of the sun
• C. Photosphere
• D. Chromosphere

Answer: (B)

Energy moves outward from the Sun’s hot core mostly by radiation in the region just outside the core. In this zone, the material is extremely dense and opaque, so photons are absorbed and re-emitted many times as they travel outward. Each interaction transfers energy to the surrounding atoms, and the random walk of countless photons results in a gradual, diffusive transfer of energy from the interior toward the outer layers.

This is different from the convection zone, where energy moves mainly through the bulk motion of hot plasma rising and cooler plasma sinking. The photosphere is the visible “surface” we see, not a primary energy-transport region, and the chromosphere is a higher, atmospheric layer. So the radiative zone is the part surrounding the core where energy transport by radiation (photon diffusion) dominates.