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Water have a chemical symbol of H2O and with structure of H-OH , so water molecule is the strangest chemical molecule where it has both acid and alkaline characters, it has(H) proton with positive charge, and (OH) with negative charge. the two opposite charges makes water molecule have dipole structure with partial positive and partial negative charge, the presence of the two oppositely charge makes water have the ability to dissolve both acidic and alkaline compounds without affecting their pH values. The second point is the relation to the density, pure water have density value of 1 gram per 1 cubic millimeter, while impure water density is more than one due to the effect of the mixed contaminants density, so swimming in sea water is easier than in lacks and reveres water, when water heated the internal water molecules spaces increases till the limit of librating some of water molecules out of the solution as vapors, and as temperature increases as the libration increases, as vapor increases also.
The density varies with temperature, but not linearly: as the temperature increases, the density rises to a peak at 3.98 °C (39.16 °F) and then decreases; this is unusual. Regular, hexagonal ice is also less dense than liquid water—upon freezing, the density of water decreases by about 9%.
Water means when you press standard temperature and ambient conditions and when 298.15 Kelvin (25 ° S) and the pressure of 100,000 Pascal (1 bar, 14.5 Bassaa, 0.99 Joe), a colorless tasteless as it is colorless when it is in small quantities, it only takes a blue color when increasing the depth of the layers, and the property in the origin and essence of water, and are caused by the selective absorption in the red area of the visible spectrum and the scattering of white light, [5] the water vapor is essentially colorless gas. [6]
Water molecular structure consists theoretically so that the oxygen atom is located in the center quad molecular geometry surfaces where hydrogen Dhirta located in addition to the couple's cyber (present on the oxygen atom) on the corners of the tetrahedral shape. But common to the molecular structure of water curved and non-linear, as an Association of H-O-H angle amount of 104.45 °. The value of the smallest of the systemic value of 109.47 tetrahedral bond angle, and is due to defend cyber couple to occupy far away as possible from each other by Vesper theory. The length of the O-H bond in the water molecule picometre 95.84. Since Electronegativity oxygen atom by Paulng scale (3.5) higher than the hydrogen atom (2.1), carry oxygen atom a partial negative charge; while the hydrogen atom bearing a partial positive charge, thus the water molecule bi-polar The determination of the pole of $ 1.84 Debye. Water can on the basis of that to form hydrogen bonds between the molecular. These factors lead to the existence of the power of a strong correlation between molecular, which explains the appearance of large water surface tension property, [7] In addition to capillary action. Explain the surface tension of water characteristic phenomenon of the possibility of parking light insect weight on the surface of the water, and the ability to form droplets; while the capillary action, which refers to the tendency of water to climb to the top of a high capillary tube is opposite to the force of gravity, important and vital property when vascular plants such as trees. [8]
Water is good polar solvents, usually referred to as a "solvent in general." Know chemicals soluble (soluble) in water as hydrophilic materials (Hedrofelih), such as salts and sugars, acids, alkalis, and some gases such as oxygen and carbon dioxide. On the other hand, you know the chemicals that are miscible with water (such as fats (oils, grease, etc.) as hydrophobic (hydrophobic). On the other hand, mixes water with many liquids Kalekhullac (eg ethanol) in all proportions, forming a combination has certain qualities, including being azeotrope (mix Oziotroba). but the contrast does not mix water with most of the organic oils, with the recent form with a density lower layer floating on the surface of the water.