"Fresh" water contains all types of salts including sodium chloride, and calcium chloride. Only distilled water contains no salts, it is pure H2O
the amount of salt dissolved in the water
Salt water is salty because of chemicals that are dissolved in the water. The water is still H2O, the same as fresh water.
salt is added, or dissolved into it, oceans are about 30 - 33%
Fresh water freezes faster than salt water because salt lowers the freezing point of water. When salt is dissolved in water, it disrupts the formation of ice crystals, requiring the salt water to become colder than fresh water in order to freeze. This phenomenon is known as the "freezing point depression."
Fresh water (of the same temperature) has the lower density ('lighter').
groundwater can be fresh, or can have various salts and/or minerals dissolved in it
Salt water contain dissolved sodium chloride; chemical and physical properties are different compared with fresh water.
Salt water is more dense than fresh water due to the presence of dissolved salts such as sodium chloride. This increased density allows objects to float higher in salt water compared to fresh water.
I would think it would dissolve faster in fresh water, as the fresh water doesn't have anything dissolved in it yet whereas the salt water has dissolved salts and so less room for the sugar molecules. A. yes; sugar does dissolve faster than salt does, in fresh water.
Freshwater has more oxygen than salt water but oxygen is more solublein fresh water.
Salt water is heavier than fresh water. The salt dissolved in salt water increases its density, making it heavier than pure water.
Salt water has a greater density than fresh water. So the same object will foat higher in salt water than in fresh, and some things will foat in salt water that are too dense to float in fresh water.