Water drops on the hydrophobic surface of grass. In chemistry, hydrophobicity is the physical property of a molecule (known as a hydrophobe) that is seemingly repelled from a mass of water. (Strictly speaking, there is no repulsive force involved; it is an absence of attraction.) In contrast, hydrophiles are attracted to water.
Ocean salinity is generally defined as the salt concentration (e.g., Sodium and Chlorure) in sea water. It is measured in unit of PSU (Practical Salinity Unit), which is a unit based on the properties of sea water conductivity. It is equivalent to per thousand or (o / 00) or to g/kg.
The salt content of water is given as parts per thousand (ppt), i.e. the amount of salt (g) dissolved in 1,000 g of water. Common salt (sodium chloride) is the main dissolved solid in seawater, and the average salinity is 35 ppt.he salt content of water is given as parts per thousand (ppt), i.e. the amount of salt (g) dissolved in 1,000 g of water. Common salt (sodium chloride) is the main dissolved solid in seawater, and the average salinity is 35 ppt.