Water

Water is a transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere, and the fluids of most living organisms.

While relatively small quantities of water appear to be colorless, pure water has a slight blue color that becomes a deeper blue as the thickness of the observed sample increases.

It forms precipitation in the form of rain and aerosols in the form of fog.

Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then become heavy enough to fall under gravity.

Water is a transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere, and the fluids of most living organisms.

The hydrosphere (from Greek ὕδωρ hydōr, "water" and σφαῖρα sphaira, "sphere" ) is the combined mass of water found on, under, and above the surface of a planet, minor planet or natural satellite.

Clouds are formed from suspended droplets of water and ice, its solid state.

Ice is water frozen into a solid state.

It forms precipitation in the form of rain and aerosols in the form of fog.

Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface.

Water moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea.

The water cycle, also known as the hydrologic cycle or the hydrological cycle, describes the continuous movement of water on, above and below the surface of the Earth.

Water moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea.

Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers.

The gaseous state of water is steam or water vapor.

Steam is water vapor, which is water in the gas phase.

Water covers 71% of the Earth's surface, mostly in seas and oceans.

An ocean is a body of water that composes much of a planet's hydrosphere.

Its chemical formula is H 2 O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds.

Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms.

Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor, clouds (formed of ice and liquid water suspended in air), and precipitation (0.001%).

Groundwater is the water present beneath Earth's surface in soil pore spaces and in the fractures of rock formations.

Its chemical formula is H 2 O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds.

Since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds.

Clouds are formed from suspended droplets of water and ice, its solid state. Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor, clouds (formed of ice and liquid water suspended in air), and precipitation (0.001%).

Water or various other chemicals may compose the droplets and crystals.

It is vital for all known forms of life, even though it provides no calories or organic nutrients.

Foods are composed chiefly of carbohydrates, fats, proteins, water, vitamins, and minerals.

Water is an excellent solvent for a wide variety of substances both mineral and organic; as such it is widely used in industrial processes, and in cooking and washing.

Washing is a method of cleaning, usually with water and often some kind of soap or detergent.

Water, ice and snow are also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, diving, ice skating and skiing.

Boat racing is a sport in which boats, or other types of watercraft, race on water.

Much of long-distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals.

Earth is the only known planet with seas of liquid water on its surface, although Mars possesses ice caps and similar planets in other solar systems may have oceans.

This effect is important in, among other things, deep-sea hydrothermal vents and geysers, pressure cooking, and steam engine design.

A hydrothermal vent is a fissure on the seafloor from which geothermally heated water issues.

It is vital for all known forms of life, even though it provides no calories or organic nutrients.

They are sourced from inorganic matter (for example, carbon dioxide, water, nitrates, phosphates, sulfates, and diatomic molecules of nitrogen and, especially, oxygen) and organic matter (carbohydrates, lipids, proteins).

Thus aquatic plants, algae, and other photosynthetic organisms can live in water up to hundreds of meters deep, because sunlight can reach them.

This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις, synthesis, "putting together".

This simplest hydrogen chalcogenide is by far the most studied chemical compound and is described as the "universal solvent" for its ability to dissolve many substances.

Water, the first chemical compound in this series, contains one oxygen atom and two hydrogen atoms, and is the most common compound on the Earth's surface.

Water is a transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere, and the fluids of most living organisms.

Some materials, such as plate glass and clean water, transmit much of the light that falls on them and reflect little of it; such materials are called optically transparent.

The word water comes from Old English wæter, from Proto-Germanic *watar (source also of Old Saxon watar, Old Frisian wetir, Dutch water, Old High German wazzar, German Wasser, Old Norse vatn, Gothic wato), from Proto-Indo-European *wod-or, suffixed form of root *wed- ("water"; "wet").

An asterisk is used to mark reconstructed words, such as *' 'water', *' 'dog', or * 'three (masculine)'; these forms are the reconstructed ancestors of the modern English words water, hound, and three.

The refraction index of liquid water (1.333 at 20 C) is much higher than that of air (1.0), similar to those of alkanes and ethanol, but lower than those of glycerol (1.473), benzene (1.501), carbon disulfide (1.627), and common types of glass (1.4 to 1.6).

Owing to the presence of three hydroxyl groups, glycerol is miscible with water and is hygroscopic nature.

Specifically, at a standard pressure of 1 atm, water is a liquid between 0 and 100 C. Increasing the pressure slightly lowers the melting point, which is about -5 C at 600 atm and -22 C at 2100 atm.

In the presence of nucleating substances, the freezing point of water is not always the same as the melting point.