Why is sea water saline
SEA WATER IS SALINE BECAUSE WATER COMES IN SEA THROUGH RIVERS AND RIVERS GET WATER BY THE MELTING ICE OF MOUNTAINS. SO WHAEN WITH SUCH A LONG JOURNEY , WATER COMES TO SEA ,IT MEET SEVERAL ROCKS WHICH HAVE SOME SODIUM AND CALCIUM SALT COVERING ON THEM AND IT COMES BY STRICKING THOSE ROCKS. SO AT LAST WHEN THE RIVER SLOWS DOWN AND JOINT TO THE SEA AND THE SEA HAS SALINE WATER
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, or 599 mM). This means that every kilogram (roughly one litre by volume) of seawater has approximately 35 grams (1.2 oz) of dissolved salts (predominantly sodium (Na+) andchloride (Cl−) ions). Average density at the surface is 1.025 g/ml. Seawater is denser than both fresh water and pure water (density 1.0 g/ml @ 4 °C(39 °F)) because the dissolved salts add mass without contributing significantly to the volume. The freezing point of seawater decreases as salt concentration increases. At typical salinity it freezes at about −2 °C (28 °F). The coldest seawater ever recorded (in a liquid state) was in 2010, in a stream under an Antarctic glacier, and measured −2.6 °C (27.3 °F).
Sea water has been defined as a weak solution of almost everything and is indeed a complex solution of mineral salts and of decayed biologic matter resulting from the teeming life in the seas. Most of the ocean's salts were derived from gradual processes such the breaking up of the cooled igneous rocks of the Earth's crust by weathering and erosion, the wearing down of mountains, and the dissolving action of rains and streams which transported their mineral washings to the sea. Some of the ocean's salts have been dissolved from rocks and sediments below its floor. Other sources of salts include the solid and gaseous materials that escaped from the Earth's crust through volcanic vents or that originated in the atmosphere.