A report on Water

A water molecule consists of two hydrogen atoms and one oxygen atom

Model of hydrogen bonds (1) between molecules of water

Overview of photosynthesis (green) and respiration (red)

An environmental science program – a student from Iowa State University sampling water

Total water withdrawals for agricultural, industrial and municipal purposes per capita, measured in cubic metres (m³) per year in 2010

$Water availability: the fraction of the population using improved water sources by country$

Roadside fresh water outlet from glacier, Nubra

Water can be used to cook foods such as noodles

Band 5 ALMA receiver is an instrument specifically designed to detect water in the universe.

South polar ice cap of Mars during Martian south summer 2000

An estimate of the proportion of people in developing countries with access to potable water 1970–2000

People come to Inda Abba Hadera spring (Inda Sillasie, Ethiopia) to wash in holy water

Icosahedron as a part of Spinoza monument in Amsterdam.

Water requirement per tonne of food product

Inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent ).

- Water

136 related topics with Alpha

Hydrogen

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Chemical element with the symbol H and atomic number 1.

Depiction of a hydrogen atom with size of central proton shown, and the atomic diameter shown as about twice the Bohr model radius (image not to scale)

Hydrogen gas is colorless and transparent, here contained in a glass ampoule.

Phase diagram of hydrogen. The temperature and pressure scales are logarithmic, so one unit corresponds to a 10x change. The left edge corresponds to 105 Pa, which is about atmospheric pressure.

Hydrogen emission spectrum lines in the visible range. These are the four visible lines of the Balmer series

NGC 604, a giant region of ionized hydrogen in the Triangulum Galaxy

Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds.

Joseph Priestley is usually given priority in the discovery.

Oxygen

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Chemical element with the symbol O and atomic number 8.

Antoine Lavoisier discredited the phlogiston theory.

Robert H. Goddard and a liquid oxygen-gasoline rocket

An experiment setup for preparation of oxygen in academic laboratories

Orbital diagram, after Barrett (2002), showing the participating atomic orbitals from each oxygen atom, the molecular orbitals that result from their overlap, and the aufbau filling of the orbitals with the 12 electrons, 6 from each O atom, beginning from the lowest-energy orbitals, and resulting in covalent double-bond character from filled orbitals (and cancellation of the contributions of the pairs of σ and σ* and π and π* orbital pairs).

Liquid oxygen, temporarily suspended in a magnet owing to its paramagnetism

Space-filling model representation of dioxygen (O2) molecule

Late in a massive star's life, 16O concentrates in the O-shell, 17O in the H-shell and 18O in the He-shell.

500 million years of climate change vs. 18O

Photosynthesis splits water to liberate and fixes into sugar in what is called a Calvin cycle.

build-up in Earth's atmosphere: 1) no produced; 2) produced, but absorbed in oceans & seabed rock; 3) starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4–5) sinks filled and the gas accumulates

Hofmann electrolysis apparatus used in electrolysis of water.

Oxygen and MAPP gas compressed-gas cylinders with regulators

An oxygen concentrator in an emphysema patient's house

Low pressure pure is used in space suits.

Most commercially produced is used to smelt and/or decarburize iron.

Water is the most familiar oxygen compound.

Oxides, such as iron oxide or rust, form when oxygen combines with other elements.

The interior of the Apollo 1 Command Module. Pure at higher than normal pressure and a spark led to a fire and the loss of the Apollo 1 crew.

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

Liquid

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Nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure.

Thermal image of a sink full of hot water with cold water being added, showing how the hot and the cold water flow into each other.

A lava lamp contains two immiscible liquids (a molten wax and a watery solution) which add movement due to convection. In addition to the top surface, surfaces also form between the liquids, requiring a tension breaker to recombine the wax droplets at the bottom.

A simulation of viscosity. The fluid on the left has a lower viscosity and Newtonian behavior while the liquid on the right has higher viscosity and non-Newtonian behavior.

A typical phase diagram. The dotted line gives the anomalous behaviour of water. The green lines show how the freezing point can vary with pressure, and the blue line shows how the boiling point can vary with pressure. The red line shows the boundary where sublimation or deposition can occur.

Structure of a classical monatomic liquid. Atoms have many nearest neighbors in contact, yet no long-range order is present.

Radial distribution function of the Lennard-Jones model fluid.

Water is by far the most common liquid on Earth.

Water cycle

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Time-mean precipitation and evaporation as a function of latitude as simulated by an aqua-planet version of an atmospheric GCM (GFDL's AM2.1) with a homogeneous “slab-ocean” lower boundary (saturated surface with small heat capacity), forced by annual mean insolation.

Global map of annual mean evaporation minus precipitation by latitude-longitude

Relationship between impervious surfaces and surface runoff

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

Hydrogen bond

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Primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group, and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac).

AFM image of naphthalenetetracarboxylic diimide molecules on silver-terminated silicon, interacting via hydrogen bonding, taken at 77 K. ("Hydrogen bonds" in the top image are exaggerated by artifacts of the imaging technique. )

An example of intermolecular hydrogen bonding in a self-assembled dimer complex. The hydrogen bonds are represented by dotted lines.

Intramolecular hydrogen bonding in acetylacetone helps stabilize the enol tautomer.

Examples of hydrogen bond donating (donors) and hydrogen bond accepting groups (acceptors)

Cyclic dimer of acetic acid; dashed green lines represent hydrogen bonds

Crystal structure of hexagonal ice. Gray dashed lines indicate hydrogen bonds

Structure of nickel bis(dimethylglyoximate), which features two linear hydrogen-bonds.

The structure of part of a DNA double helix

Hydrogen bonding between guanine and cytosine, one of two types of base pairs in DNA

A strand of cellulose (conformation Iα), showing the hydrogen bonds (dashed) within and between cellulose molecules

The hydrogen bond is responsible for many of the abnormal physical and chemical properties of compounds of N, O, and F. In particular, intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group-16 hydrides that have much weaker hydrogen bonds.

Groundwater

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Dzherelo, a common source of drinking water in a Ukrainian village

The entire surface water flow of the Alapaha River near Jennings, Florida, going into a sinkhole leading to the Floridan Aquifer groundwater

Groundwater may be extracted through a water well

Diagram of a water balance of the aquifer

Iron (III) oxide staining (after water capillary rise in a wall) caused by oxidation of dissolved iron (II) and its subsequent precipitation, from an unconfined aquifer in karst topography. Perth, Western Australia.

Groundwater withdrawal rates from the Ogallala Aquifer in the Central United States

Center-pivot irrigated fields in Kansas covering hundreds of square miles watered by the Ogallala Aquifer

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

Chemical element

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Species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species.

$Estimated distribution of dark matter and dark energy in the universe. Only the fraction of the mass and energy in the universe labeled "atoms" is composed of chemical elements.$

Periodic table showing the cosmogenic origin of each element in the Big Bang, or in large or small stars. Small stars can produce certain elements up to sulfur, by the alpha process. Supernovae are needed to produce "heavy" elements (those beyond iron and nickel) rapidly by neutron buildup, in the r-process. Certain large stars slowly produce other elements heavier than iron, in the s-process; these may then be blown into space in the off-gassing of planetary nebulae

Abundances of the chemical elements in the Solar System. Hydrogen and helium are most common, from the Big Bang. The next three elements (Li, Be, B) are rare because they are poorly synthesized in the Big Bang and also in stars. The two general trends in the remaining stellar-produced elements are: (1) an alternation of abundance in elements as they have even or odd atomic numbers (the Oddo-Harkins rule), and (2) a general decrease in abundance as elements become heavier. Iron is especially common because it represents the minimum energy nuclide that can be made by fusion of helium in supernovae.

Mendeleev's 1869 periodic table: An experiment on a system of elements. Based on their atomic weights and chemical similarities.

Air is primarily a mixture of the elements nitrogen, oxygen, and argon, though it does contain compounds including carbon dioxide and water.

Surface runoff

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Surface runoff from a hillside after soil is saturated

Precipitation washing contaminates into local streams

Willow hedge strengthened with fascines for the limitation of runoff, north of France.

Soil erosion by water on intensively-tilled farmland.

Runoff holding ponds (Uplands neighborhood of North Bend, Washington)

Surface runoff (also known as overland flow) is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil.

Ball-and-stick model of the diamminesilver(I) cation, [Ag(NH3)2]+

Ammonia

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Compound of nitrogen and hydrogen with the formula NH3.

Ball-and-stick model of the tetraamminediaquacopper(II) cation, [Cu(NH3)4(H2O)2](2+)

This high-pressure reactor was built in 1921 by BASF in Ludwigshafen and was re-erected on the premises of the University of Karlsruhe in Germany.

Ammoniacal Gas Engine Streetcar in New Orleans drawn by Alfred Waud in 1871.

The X-15 aircraft used ammonia as one component fuel of its rocket engine

Anti-meth sign on tank of anhydrous ammonia, Otley, Iowa. Anhydrous ammonia is a common farm fertilizer that is also a critical ingredient in making methamphetamine. In 2005, Iowa used grant money to give out thousands of locks to prevent criminals from getting into the tanks.

The world's longest ammonia pipeline (roughly 2400 km long), running from the TogliattiAzot plant in Russia to Odessa in Ukraine

Hydrochloric acid sample releasing HCl fumes, which are reacting with ammonia fumes to produce a white smoke of ammonium chloride.

Production trend of ammonia between 1947 and 2007

Main symptoms of hyperammonemia (ammonia reaching toxic concentrations).

Ammonia occurs in the atmospheres of the outer giant planets such as Jupiter (0.026% ammonia), Saturn (0.012% ammonia), and in the atmospheres and ices of Uranus and Neptune.

Solvent properties: Ammonia readily dissolves in water. In an aqueous solution, it can be expelled by boiling. The aqueous solution of ammonia is basic. The maximum concentration of ammonia in water (a saturated solution) has a density of 0.880 g/cm3 and is often known as '.880 ammonia'.

Drinking water

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Drinking water vending machines in Thailand. One litre of potable water is sold (into the customer's own bottle) for 1 baht.

EPA drinking water security poster from 2003

Solar water disinfection application in Indonesia

World map for SDG 6 Indicator 6.1.1 in 2015: "Proportion of population using safely managed drinking water services"

% of the population with access to drinking water

Population in survey regions living without safely managed drinking water as reported by the WHO/UNICEF JMP.

Project in Nepal: unboxing the water filter unit.

Illustration of a typical tap water treatment process

Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water.