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Sentence | No. 8 Explorer
Editor|Explorer No. 8
Seawater vs. freshwater
Seawater, as the name suggests, is water from the sea, which is rich in elements, and there are even more elements in seawater than in freshwater.
The sea water is rich in marine fish, and in places where people do not live, the abundant fish in the sea water provide abundant food resources for human beings.
According to the existing scientific research, life originated from a single cell in seawater, in ancient times the earth was mainly an ocean, in the ocean was born the source of life, seawater is very important to the production of people, and it can even be said that seawater is the birthplace of human life.
There is also an important substance in seawater – salt.
The main components in seawater are sodium, magnesium, calcium, potassium, strontium, chlorine, sulfate, bicarbonate, bromine, fluorine, and there is also a component in seawater, boric acid molecules, the source of this type of composition is the most special, mainly from the trace elements after rock weathering and volcanic eruptions, these substances are transported into the sea by rivers, forming boric acid molecules in seawater.
The salt content of fresh water is very low, and most of the inland lakes and rivers are freshwater, and fresh water is the main source of drinking water for the human body.
Can you drink it?
Fresh water can be directly drunk, or can be directly drunk after simple treatment, and seawater can not be drunk, drinking seawater will also have a certain impact on the human body, the treatment of seawater is difficult, a lot of cost and capital need to be invested, the current mode of seawater into drinking water, is rarely put into use due to technical limitations.
Seawater can not be drunk directly, because the salt content in seawater is large, and it also contains a variety of other elements, and the element content in seawater exceeds the standard of drinking water, and drinking seawater has a certain impact on the human body.
The concentration of salt in seawater is too large, and the solution has a tendency to flow from low concentration to high concentration, and people drink high concentration of seawater, and the water in the body will be affected by seawater, especially when people are thirsty, drinking seawater will be more thirsty.
The concentration of elements in seawater is too high, and the human body needs to drink more water to dilute the elements in the body in order to excrete the high concentration of elements.
Compared with the high concentration of elements in seawater, the elements in freshwater are not only moderate, but also more in line with the trace element value required by the human body.
Compared with seawater, which still needs to be treated before it can be drunk, fresh water only needs to be simply treated by the human body to drink, and fresh water is more suitable for human survival and drinking.
The taste of seawater is not good, it tastes salty and bitter, seawater is not suitable for people's taste, it is difficult for normal people to swallow seawater, and drinking seawater for a long time is a challenge for people's body and spirit.
Fresh water tastes none, making it more suitable for human drinking.
The color of sea water and fresh water
The color of the sea water is blue, the same color as the blue sky, compared to the colorless or even cyan color of fresh water, why is the sea water blue?
The color of seawater is blue from afar, but the color is colorless up close, and the color of seawater is blue because of the selective absorption of light and the scattering of light.
When sunlight hits the surface of the water, part of the light is reflected back, and part of the light is refracted into the sea, and the water is selectively absorbent of light, and the light that enters the water will be absorbed in the process of propagation.
Red light and yellow light are the easiest to be absorbed by seawater, and green light is easily absorbed by seawater.
The color of the sea water varies from region to region, with some areas looking darker and some areas looking lighter, and the scattering of light will be stronger when the water is deeper, and the water will look darker in deep areas.
In shallower waters, the color of the water will appear bluish and bluish overall.
The color of freshwater is mostly blue-yellow, the closer the color of freshwater is to yellow, the more organic matter in the water, freshwater is mostly lakes and rivers, the range of water is smaller than that of seawater, compared to the depth of seawater, freshwater is relatively shallow, can not scatter blue light, and it looks blue in freshwater is very "rare".
buoyancy
Buoyancy refers to the upward force experienced by an object in a fluid, and the higher the density of the fluid, the greater the upward force.
The buoyancy of seawater is greater than that of freshwater, and the density of seawater is greater than that of freshwater.
Water basically has buoyancy, the elements of seawater are abundant, the density in seawater is greater, relatively speaking, the buoyancy of seawater will be greater, freshwater is evaporated and circulated by seawater, and there are fewer elements in freshwater, the density is smaller, and the buoyancy is also smaller.
Seawater and freshwater are also different in terms of buoyancy.
There are differences between seawater and freshwater in terms of whether they are drinkable or not, and there are differences in the color they seem.
Not only that, but seawater and freshwater have different buoyancy due to their different densities.
Seawater and freshwater look similar, and even have certain differences in physical properties, but in reality there are big differences.