As water flows in rivers, it picks up small amounts of mineral salts from the rocks and soil of the river beds. This very-slightly salty water flows into the oceans and seas. The water in the oceans only leaves by evaporating (and the freezing of polar ice), but the salt remains dissolved in the ocean - it does not evaporate. So the remaining water gets saltier and saltier as time passes.
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The ocean is salty because of the gradual concentration of dissolved chemicals eroded from the Earth's crust and washed into the sea. Solid and gaseous ejections from volcanoes, suspended particles swept to the ocean from the land by onshore winds, and materials dissolved from sediments deposited on the ocean floor have also contributed. Salinity is increased by evaporation or by freezing of sea ice and it is decreased as a result of rainfall, runoff, or the melting of ice. The average salinity of sea water is 35 o/oo, but concentrations as high as 40 o/oo are observed in the Red Sea and the Persian Gulf. Salinities are much less than average in coastal waters, in the polar seas, and near the mouths of large rivers.
Sea water not only is much saltier than river water but it also differs in the proportion of the various salts. Sodium and chloride constitute 85 percent of the dissolved solids in sea water and account for the characteristic salty taste. Certain constituents in sea water, such as calcium, magnesium, bicarbonate, and silica, are partly taken out of solution by biological organisms, chemical precipitation, or physical-chemical reactions. In open water the chemical composition of sea water is nearly constant. Because of the stable ratios of the principal constituents to total salt content, the determination of one major constituent can be used to calculate sea water salinity. For minor constituents and dissolved gases the composition is variable and therefore ratios cannot be used to calculate salt Circulation and mixing, density and ocean currents, wind action, water temperature, solubility, and biochemical reactions are some of the factors that explain why the composition of water in the open sea is almost constant from place to place.
Sea water not only is much saltier than river water but it also differs in the proportion of the various salts. Sodium and chloride constitute 85 percent of the dissolved solids in sea water and account for the characteristic salty taste. Certain constituents in sea water, such as calcium, magnesium, bicarbonate, and silica, are partly taken out of solution by biological organisms, chemical precipitation, or physical-chemical reactions. In open water the chemical composition of sea water is nearly constant. Because of the stable ratios of the principal constituents to total salt content, the determination of one major constituent can be used to calculate sea water salinity. For minor constituents and dissolved gases the composition is variable and therefore ratios cannot be used to calculate salt Circulation and mixing, density and ocean currents, wind action, water temperature, solubility, and biochemical reactions are some of the factors that explain why the composition of water in the open sea is almost constant from place to place.
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see above. Its correct.