Correct Option
The correct option is (a) 1 only.
Explanation
Evaporation is the physical phase transition of water from a liquid state to a gaseous state (water vapor). In the context of the global hydrological cycle, this process is driven by thermal energy and plays a critical role in regulating ocean salinity and atmospheric moisture.
Statement 1 is Correct:
Evaporation is the primary natural mechanism for separating pure water from dissolved salts in seawater. During this process, only water molecules transition into the vapor phase, while the dissolved salts and other impurities remain behind. This separation is the fundamental basis of the water cycle, resulting in the formation of freshwater clouds and precipitation.
Statement 2 is Incorrect:
The heat required for evaporation (latent heat of vaporization) does not come solely from the internal heat of the ocean water. The primary source of energy for the evaporation of seawater is solar radiation (the Sun). While the water body retains thermal energy, the continuous process of evaporation on a global scale is driven by external solar heating, which warms the surface layer of the oceans.
Key Takeaway:
Evaporation is a physical process driven primarily by solar energy that separates fresh water from saline ocean water, leaving salts behind.