Final answer:
The process of obtaining sea salt by allowing the sun to evaporate water in lagoons is a natural form of desalination which is crucial in areas with limited freshwater resources. Desalination can be achieved through methods including evaporation and condensation, freezing, and reverse osmosis.
Step-by-step explanation:
The method described for obtaining sea salt involves capturing ocean water in large flat lakes known as lagoons where the sun evaporates the water, leaving behind crystallized sea salt. This process is similar to natural desalination, which can also refer to various methods used to remove salt from water to produce fresh water for human use. Desalination plays a critical role in areas where freshwater is scarce.
An important part of the water cycle is the evaporation of water, a key step in desalination. Evaporation occurs when water changes from a liquid to a gas at ambient temperatures, a process that results in nearly pure water vapor with very few dissolved ions. The dissolved ions, such as sodium and chloride in the case of seawater, are left behind in the remaining water, becoming more concentrated until they eventually precipitate out as salt crystals.
Only about 1% of the Earth's water is available as freshwater, despite the planet being largely covered by water because of its salt content. Desalination can take several forms, including freeze-thaw methods, distillation through evaporation and condensation, and filtration through reverse osmosis membranes. Each process leverages different physical properties and scientific phenomena to separate pure water from dissolved salts and other impurities.