Sunlight serves as the energy source for which processes in water bodies?

• A. Temperature Change and Evaporation
• B. Dissolution
• C. Color Change
• D. Tidal Motion

Answer: (A)

Sunlight provides energy as heat that directly raises water temperature and fuels evaporation. When the sun shines, surface water absorbs solar radiation, increasing the kinetic energy of water molecules and raising the temperature. The added energy also helps water molecules overcome vapor pressure, allowing them to escape as vapor, which is evaporation. These are direct, heat-driven processes powered by solar energy. In contrast, dissolution depends on solvent–solute interactions and temperature-dependent solubility rather than sunlight as its primary energy source. Color changes in water bodies come from pigments, suspended matter, or biological activity, not from sunlight supplying energy for the change itself. Tidal motion arises from gravitational forces between the Earth, Moon, and Sun, with energy derived from gravity, not from solar radiation.