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.
Remember that % is the symbol for percent or parts per hundred -- divide % by ten or add another zero in the denominator and you have parts per thousand. Thus, a salinity value of 35 o /oo means 35 parts of dissolved salt per 1,000 parts of sea water. Similarly, a sodium (Na +) concentration of 10 o /oo means 10 pounds of sodium per 1,000 pounds of water. The salinity of sea water exhibits a variation around an average value of 35.5 o /oo in the world's oceans depending on the balance between evaporation (increasing salinity) and precipitation (decreasing salinity).