GEOLOGY

Detailed explanation-1: -Dissolving salt in water increases both the mass and volume of the water, but it increases the mass more. Because D = m/v, increasing the mass more than the volume results in an increase in density.

Detailed explanation-2: -Salt is a solid chemical compound. Take a lump of rock salt of sodium chloride, throw it into the water: it will sink to the bottom. The reason is that the density of sodium chloride with more than 2 g/cm3 is higher than the density of seawater less than 1.1 g/cm3.

Detailed explanation-3: -Salt water is more dense than fresh water Salt water has more stuff in it than fresh water. That stuff would be the salt, which makes the mass of water greater, without adding much to its volume. Density = mass/volume. Increasing the mass by adding salt increases the density.

Detailed explanation-4: -The reason is: Buoyancy – saltwater gives more buoyancy than freshwater because of the higher density of saltwater. Buoyancy makes it easy for the body to stay high in water, thus all other factors being kept equal, one can swim faster in salt water than in freshwater.

Detailed explanation-5: -One is simply that the NaCl is much denser than water to begin with, mainly because its ions have more mass than the oxygen and hydrogen atoms in the water molecules. Also, the ions bind nicely with the water molecules, so that the volume of the saltwater isn’t as big as the water volume plus the salt volume.