sea water is less denser than river water.
A lower freezing point than fresh water
Seawater is more dense than air. That is why the air rests on top of the seawater and not the other way around.
It is lighter than water
Because it is lighter than water.
something lighter than water
It is lighter than water.
It is easier to float, in any case, because salt water has a greater density.
We know that the density of the sea water is more than the density of the river water. So, the weight of displaced sea water is more than the weight of displaced river water. This weight gives the upward Buoyant force to the swimmer. Thus, the apparent weight of the swimmer is less in the sea water. Hence he finds it easier to swim in the sea water.
Answer 1) At the Surface. Answer 2) I disagree with the above answer. For practical purposes water is not compressible. Therefore the density is the same all over. The difference in density at the surface and at the bottom is so small that it is negligible. However, fresh water is less dense than seawater, since the salts dissolved in the seawater makes it more dense. For that reason, if you consider seawater near the mouth of a river, that water will be less dense than the seawater in general.
Seawater dissolves more than fresh water because of the salinity in the water.
Sea water contains much more dissolved material like salt (The Pacific has more than 33 g NaCl per liter) and other stuff than river water does (<0.5 g/L).
it is lighter than water.
It is better to use the muddy puddle water than the seawater because of the salt
Seawater is more dense than freshwater. Therefore the seawater would sink lower than the freshwater. Ships do indeed stay higher in seawater because of the higher density or specific gravity of seawater over freshwater
A lower freezing point than fresh water
Seawater because it contains salt which makes the water more dense than water which does not contain salt.
Water is actually a weak insulator and does not transmit current well unless it has ions in it, like saltwater does. Seaweeds are limited in their abilities to conduct electricity per se, but as they come from saltwater, the salts still present on their "leaves" conduct relatively well.