The viscosity of water is the physical properties of water that should not be overlooked. This is a result of friction caused by the arrest of a liquid substance on moving objects. The amount of friction is proportional to the prisoners:
a) The surface area of objects associated with water.
b) The speed of motion of a body.
c) The constant that depends on the temperature and the properties of the liquid.
Factors that affect the viscosity of water, among others, is the temperature. Temperature factors greatly affect the viscosity of the water, if the temperature rises, the viscosity of water is decreased, the viscosity of water at a temperature of 0ºC two times greater than the temperature of 25ºC in the same state of other factors (Table 2). The bodies of plankton at a temperature of 25ºC will sink two times faster than 0ºC.
Table 2. The relationship between water viscosity with temperature.
The viscosity of water is approximately 100 times greater than in the air, water animals have to cope with greater pressure when compared to the animals that live in the air. This shows that the viscosity of water can determine:
a) The habit of living organisms.
b) body shape (morphology) of aquatic animals.
c) Use of energy by water animals.
d) It is a major barrier to the movement.
Water Surface Tension
Water surface tension arising from the activity of water molecules that are not balanced on and below the surface of the water. Water molecules that have affinity towards neighboring molecules, although they have a tendency to move on their own. In the liquid phase, the power of attraction is still large enough so that the molecules of the liquid substance still want to get together, which is called the nature of cohesion within the liquid.
On the surface contact with the air, there are few water molecules that escape from its bond with other molecules called evaporation. Affinity to each of these molecules into every corner, the average is the same. Only against adjacent molecules on the surface alone is not the case. There is only attraction that leads to the fluid and leading to the side only, and power was causing a tension in the surface layer of the water.
At this water level there will be a voltage also forming a kind of “skin” surface. Animals and plants that light can walk or move over “skin” surface water.