File Name: water and human body .zip
Drinking water , also known as potable water , is water that is safe to drink or use for food preparation. The amount of drinking water required to maintain good health varies, and depends on physical activity level, age, health-related issues, and environmental conditions. Typically in developed countries , tap water meets drinking water quality standards, even though only a small proportion is actually consumed or used in food preparation. Other typical uses include washing, toilets, and irrigation. Greywater may also be used for toilets or irrigation.
Water is an 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 .
It is vital for all known forms of life , even though it provides no calories or organic nutrients. Its chemical formula is H 2 O, meaning that each of its molecules contains one oxygen and two hydrogen atoms , connected by covalent bonds. Two hydrogen atoms are attached to one oxygen atom at an angle of It forms precipitation in the form of rain and aerosols in the form of fog.
Clouds are formed from suspended droplets of water and ice , its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water moves continually through the water cycle of evaporation , transpiration evapotranspiration , condensation , precipitation , and runoff , usually reaching the sea. Water plays an important role in the world economy. Much of the long-distance trade of commodities such as oil, natural gas, and manufactured products is transported by boats through seas , rivers , lakes , and canals.
Large quantities of water, ice, and steam are used for cooling and heating , in industry and homes. 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.
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.
Water H 2 O is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, nearly colorless with a hint of blue. 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 is the only common substance to exist as a solid , liquid, and gas in normal terrestrial conditions. Along with oxidane , water is one of the two official names for the chemical compound H 2 O ;  it is also the liquid phase of H 2 O.
The addition or removal of heat can cause phase transitions : freezing water to ice , melting ice to water , vaporization water to vapor , condensation vapor to water , sublimation ice to vapor and deposition vapor to ice. Water differs from most liquids in that it becomes less dense as it freezes. This ice insulates the water below, preventing it from freezing solid.
Without this protection, most aquatic organisms would perish during the winter. However, even below the boiling point, water can change to vapor at its surface by evaporation vaporization throughout the liquid is known as boiling.
Sublimation and deposition also occur on surfaces. The melting and boiling points depend on pressure. A good approximation for the rate of change of the melting temperature with pressure is given by the Clausius—Clapeyron relation :. In most substances, the volume increases when melting occurs, so the melting temperature increases with pressure. However, because ice is less dense than water, the melting temperature decreases.
High-altitude cooking takes longer than sea-level cooking. These meet at a single point called the triple point , where all three phases can coexist. The triple point is at a temperature of Until , the triple point was used to define the Kelvin temperature scale. At higher temperatures and pressures the liquid and vapor phases form a continuous phase called a supercritical fluid. It can be gradually compressed or expanded between gas-like and liquid-like densities, its properties which are quite different from those of ambient water are sensitive to density.
For example, for suitable pressures and temperatures it can mix freely with nonpolar compounds , including most organic compounds. This makes it useful in a variety of applications including high-temperature electrochemistry and as an ecologically benign solvent or catalyst in chemical reactions involving organic compounds.
In Earth's mantle, it acts as a solvent during mineral formation, dissolution and deposition. The normal form of ice on the surface of Earth is Ice Ih , a phase that forms crystals with hexagonal symmetry. Another with cubic crystalline symmetry , Ice Ic , can occur in the upper atmosphere. As of , 17 have been experimentally confirmed and several more are predicted theoretically. The details of the chemical nature of liquid water are not well understood; some theories suggest that its unusual behaviour is due to the existence of 2 liquid states.
Pure water is usually described as tasteless and odorless, although humans have specific sensors that can feel the presence of water in their mouths,  and frogs are known to be able to smell it. Humans and other animals have developed senses that enable them to evaluate the potability of water by avoiding water that is too salty or putrid. Pure water is visibly blue due to absorption of light in the region ca.
The principal absorption bands responsible for the color are overtones of the O-H stretching vibrations. The apparent intensity of the color increases with the depth of the water column, following Beer's law. This also applies, for example, with a swimming pool when the light source is sunlight reflected from the pool's white tiles. In nature, the color may also be modified from blue to green due to the presence of suspended solids or algae. In industry, near-infrared spectroscopy is used with aqueous solutions as the greater intensity of the lower overtones of water means that glass cuvettes with short path-length may be employed.
Aquatic plants , algae , and other photosynthetic organisms can live in water up to hundreds of meters deep, because sunlight can reach them. The refractive index of liquid water 1. The refraction index of ice 1. In a water molecule, the hydrogen atoms form a The hydrogen atoms are close to two corners of a tetrahedron centered on the oxygen. At the other two corners are lone pairs of valence electrons that do not participate in the bonding.
In a perfect tetrahedron, the atoms would form a Other substances have a tetrahedral molecular structure, for example, methane CH 4 and hydrogen sulfide H 2 S. However, oxygen is more electronegative holds on to its electrons more tightly than most other elements, so the oxygen atom retains a negative charge while the hydrogen atoms are positively charged.
Along with the bent structure, this gives the molecule an electrical dipole moment and it is classified as a polar molecule. Water is a good polar solvent , that dissolves many salts and hydrophilic organic molecules such as sugars and simple alcohols such as ethanol. Water also dissolves many gases, such as oxygen and carbon dioxide —the latter giving the fizz of carbonated beverages, sparkling wines and beers. In addition, many substances in living organisms, such as proteins , DNA and polysaccharides , are dissolved in water.
The interactions between water and the subunits of these biomacromolecules shape protein folding , DNA base pairing , and other phenomena crucial to life hydrophobic effect. Many organic substances such as fats and oils and alkanes are hydrophobic , that is, insoluble in water. Many inorganic substances are insoluble too, including most metal oxides , sulfides , and silicates.
Because of its polarity, a molecule of water in the liquid or solid state can form up to four hydrogen bonds with neighboring molecules.
Hydrogen bonds are about ten times as strong as the Van der Waals force that attracts molecules to each other in most liquids. This is the reason why the melting and boiling points of water are much higher than those of other analogous compounds like hydrogen sulfide. They also explain its exceptionally high specific heat capacity about 4. These properties make water more effective at moderating Earth's climate , by storing heat and transporting it between the oceans and the atmosphere.
These bonds are the cause of water's high surface tension  and capillary forces. The capillary action refers to the tendency of water to move up a narrow tube against the force of gravity. This property is relied upon by all vascular plants , such as trees. Pure water has a low electrical conductivity , which increases with the dissolution of a small amount of ionic material such as common salt.
Liquid water can be split into the elements hydrogen and oxygen by passing an electric current through it—a process called electrolysis. The decomposition requires more energy input than the heat released by the inverse process Liquid water can be assumed to be incompressible for most purposes: its compressibility ranges from 4.
Sound travels long distances in water with little attenuation, especially at low frequencies roughly 0. Metallic elements which are more electropositive than hydrogen, particularly the alkali metals and alkaline earth metals such as lithium , sodium , calcium , potassium and cesium displace hydrogen from water, forming hydroxides and releasing hydrogen.
At high temperatures, carbon reacts with steam to form carbon monoxide and hydrogen. Hydrology is the study of the movement, distribution, and quality of water throughout the Earth. The study of the distribution of water is hydrography. The study of the distribution and movement of groundwater is hydrogeology , of glaciers is glaciology , of inland waters is limnology and distribution of oceans is oceanography. Ecological processes with hydrology are in the focus of ecohydrology.
The collective mass of water found on, under, and over the surface of a planet is called the hydrosphere. Earth's approximate water volume the total water supply of the world is 1. Liquid water is found in bodies of water , such as an ocean, sea, lake, river, stream, canal , pond, or puddle. The majority of water on Earth is sea water. Water is also present in the atmosphere in solid, liquid, and vapor states. It also exists as groundwater in aquifers. Water is important in many geological processes.
Groundwater is present in most rocks , and the pressure of this groundwater affects patterns of faulting. Water in the mantle is responsible for the melt that produces volcanoes at subduction zones.
On the surface of the Earth, water is important in both chemical and physical weathering processes. Water, and to a lesser but still significant extent, ice, are also responsible for a large amount of sediment transport that occurs on the surface of the earth. Deposition of transported sediment forms many types of sedimentary rocks , which make up the geologic record of Earth history.
The water cycle known scientifically as the hydrologic cycle refers to the continuous exchange of water within the hydrosphere , between the atmosphere , soil water, surface water , groundwater , and plants. Water moves perpetually through each of these regions in the water cycle consisting of the following transfer processes:. Precipitation, at a rate of Tt per year over land, has several forms: most commonly rain, snow, and hail , with some contribution from fog and dew.
Victorian government portal for older people, with information about government and community services and programs. Type a minimum of three characters then press UP or DOWN on the keyboard to navigate the autocompleted search results. The human body can last weeks without food, but only days without water. The body is made up of 50 to 75 per cent water. Water forms the basis of blood, digestive juices, urine and perspiration, and is contained in lean muscle, fat and bones. The amount we need depends on our body size, metabolism, the weather, the food we eat and our activity levels. Most foods, even those that look hard and dry, contain water.
Nitrate is a compound that naturally occurs and has many human-made sources. Nitrate is in some lakes, rivers, and groundwater in Minnesota. You cannot taste, smell, or see nitrate in water. Consuming too much nitrate can be harmful—especially for babies. Consuming too much nitrate can affect how blood carries oxygen and can cause methemoglobinemia also known as blue baby syndrome.
Getting enough water every day is important for your health. Drinking water can prevent dehydration, a condition that can cause unclear thinking, result in mood change, cause your body to overheat, and lead to constipation and kidney stones. Most of your fluid needs are met through the water and beverages you drink. You can get some fluids through the foods that you eat — especially foods with high water content, such as many fruits and vegetables. Of course there are many other beverage options besides water, and many of these can be part of a healthy diet.
The human body can resist only a few days without water without The human body is 70% – 90% water. tapnetwork2015.org
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This substance makes up a majority of your body weight and is involved in many important functions, including:. You get most of your water from drinking beverages, but food also contributes a small amount to your daily water intake. Water is a main component of saliva. Saliva also includes small amounts of electrolytes, mucus, and enzymes. Your body generally produces enough saliva with regular fluid intake. However, your saliva production may decrease as a result of age or certain medications or therapies.
Water makes up more than two-thirds of the weight of the human body. Without water, humans would die in a few days. All the cells and organs need water to function. Water serves as a lubricant.
Drinking enough water every day is good for overall health. As plain drinking water has zero calories, it can also help with managing body weight and reducing caloric intake when substituted for drinks with calories, like regular soda. Top of Page. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Section Navigation. Facebook Twitter LinkedIn Syndicate.
The distribution of body water varies under different circumstances, but the total amount in the body remains relatively constant. Water Balance. The.
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