Why is the water green and why are some rivers green?

The scattering effect of water molecules on various wavelengths of light (referring to red, orange, yellow, green, cyan, blue, violet) in visible light (refers to the phenomenon that part of the light rays disperses and propagates from the original direction when the beam advances in the medium), and its scattering effect on short wavelengths (such as green, cyan, blue, etc.) is much stronger than that of light with long wavelengths (such as red and orange). In addition, the strength of the scattering effect is also related to the length of the optical path. When the water layer is shallow, almost all wavelengths of light in the visible light can be transmitted, and the scattering effect is not significant.

Therefore, water is colorless and transparent. When the water is deep, the water appears pale blue-green due to significant scattering. The more air dissolved in the water, the greener it is.

When the water is deeper, it will appear dark blue or even black. This is why the water is blue when it is deeper.

It has to do with the depth of the water A small amount of water is colorless and transparent, and the water in lakes and rivers is mostly green, while the ocean, is blue, or dark blue, and the amount of water that can make light visible.

The intensity of scattering varies depending on the intensity of the scattering, and multiple scattering causes the various rays of light in the visible light to be weakened or absorbed.

Aquatic weeds as well as underwater sediments.

The water of the river (lake) reflects the color of the mountains on the shore, and the plants and algae-like plants in the water are more likely to grow, so the river water is mostly green.

Seawater is different. Seawater is transparent, when sunlight is transmitted into seawater, it is decomposed into red, orange, yellow, green, cyan, blue, purple seven colors of light, seawater can absorb red, orange and yellow rays with longer wavelengths, and less absorb blue and purple light with shorter wavelengths, so blue and violet light can be transmitted to very deep sea, and it is easy to be scattered by seawater molecules, so people see that seawater is dark blue.

There are some lower plants that grow, such as blue-green algae.

It contains a lot of algae and is green.

First, the oxygen in the air in the river flow will be dissolved in the water, so that the oxygen in the water will cause the green algae to grow, which will look dark green to the naked eye.

Second, due to the pollution of wastewater from surrounding factories and residential garbage, the river has excessive nitrogen, phosphorus and potassium content in the water body, resulting in eutrophication of the water body. At this time, the green algae in the water body will grow wildly, and a large dark green patch will appear.

Third, the physical phenomenon is that the refraction of light in water makes it appear green to the naked eye.

The bottom of the river is mostly aquatic plants and the like. So it's green on the back. The river water is green because there are algae that perform photosynthesis in the river water.

Selective absorption is the main reason why objects show color. In a certain wavelength range, if a substance absorbs an equal amount (referring to energy) of light of various wavelengths passing through it, and the absorption amount is very small, the substance is called general absorption; If a substance absorbs a certain wavelength of light energy significantly, it is said that the substance has selective absorption. When sunlight hits the surface of the sea, some of the light is reflected back and the other part is refracted into the water.

The light that enters the water is absorbed by the water during its propagation. The absorption of light by water is related to the wavelength of the light, i.e., water has selective absorption. Water absorbs light with longer wavelengths significantly, but not with shorter wavelengths.

Red, orange and yellow light are all absorbed at different depths and increase the temperature of the seawater. To a certain depth the green light is also absorbed.

Because the water is not pure water, and the depth of the water is relatively large, when the thickness of the water layer exceeds 2 meters, the color of the water will change due to the refraction and reflection of light, and there are some algae and microorganisms in the water, so it appears turquoise. The reflection of light makes up the electromagnetic waves of sunlight at different wavelengths, and different objects reflect electromagnetic waves of different wavelengths. It's the same as the fact that the sea is blue.

Water: Water is an inorganic substance composed of hydrogen and oxygen, which is non-toxic and drinkable. It is a colorless and odorless transparent liquid at room temperature and pressure, which is known as the source of human life and is an important substance to maintain life.

Water is one of the most common substances on Earth. 71% of the Earth's surface is covered by water. It is an important resource for the survival of all life, including inorganic chemistry and human beings, and it is also the most important component of living organisms.

Pure water is a very weak electrolyte with very weak electrical conductivity. Water in daily life has more anions and cations due to the dissolution of other electrolytes, so it has more obvious conductivity.