In my language i can say water is the only water that nothing will replace to water in any ways or any where or any position in the world. water is life for every creature in the world that you can not live with out water. we may live for a long period with out food, but with out water we can't.
Water is one of the most important needs of living things. It is second only to the air we breathe. In fact, some scientists believe that all life began in water. Today, our space explorations have found signs that water exists not only on Earth but throughout the universe. If this is so, it may be that living things exist or have existed on these other planets.
Water Existing States.
Water is a liquid at the temperatures and pressures that are most adequate for life. Specifically, at a standard pressure of 1 atmospheric pressure & water is a liquid between 0 °C and 100 °C.
Avaibility In the Earth.
Water is the most abundant liquid on Earth. It covers more than 70% of the earth's surface. Including the clouds (which are, of course, also water), it makes our entire planet look blue and white from space.
The water on the surface of Earth is found mainly in its oceans (97.25 percent) and polar ice caps and glaciers (2.05 percent), with the balance in freshwater lakes, rivers, and groundwater.
As Earth’s population grows and the demand for fresh water increases, water purification and recycling become increasingly important. Interestingly, the purity requirements of water for industrial use often exceed those for human consumption.
Forms Of Water.
- It can be vapor - as the steam from your breath or cooking, or unseen as humidity in the air.
- It can be liquid - as a beverage or a lake, stream, river or ocean.
- It can be solid - as ice.
Taste, Color and odor
Pure water is usually tasteless, colorless 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. However, water from ordinary sources (including bottled mineral water) usually has many dissolved substances, that may give it varying tastes and odors. 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.
Structure Of Water
The water molecule is composed of two hydrogen atoms, each linked by a single chemical bond to an oxygen atom. Most hydrogen atoms have a nucleus consisting solely of a proton. Two isotopic forms, deuterium and tritium, in which the atomic nuclei also contain one and two neutrons, respectively, are found to a small degree in water. Deuterium oxide (D2O), called heavy water, is important in chemical research and is also used as a neutron moderator in some nuclear reactors.
Although its formula (H2O) seems simple, water exhibits very complex chemical and physical properties.
The water molecule is not linear but bent in a special way. The two hydrogen atoms are bound to the oxygen atom at an angle of 104.5°.
The O−H distance (bond length) is 95.7 picometres (9.57 × 10−11 metres, or 3.77 × 10−9 inches). Because an oxygen atom has a greater electronegativity than a hydrogen atom, the O−H bonds in the water molecule are polar, with the oxygen bearing a partial negative charge (δ−) and the hydrogens having a partial positive charge (δ+).
Hydrogen atoms in water molecules are attracted to regions of high electron density and can form weak linkages, called hydrogen bonds, with those regions. This means that the hydrogen atoms in one water molecule are attracted to the nonbonding electron pairs of the oxygen atom on an adjacent water molecule. The structure of liquid water is believed to consist of aggregates of water molecules that form and re-form continually. This short-range order, as it is called, accounts for other unusual properties of water, such as its high viscosity and surface tension.
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