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| Sunday, 20 March 2005 |
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Junior Observer |
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News Business Features
Editorial
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Water - the source of all life
So, what is it about water that makes it so important to us? And what is it about water that makes it water? You probably know that the chemical description of water is H2O, that is, one atom of oxygen bound to two atoms of hydrogen.The hydrogen atoms are "attached" to one side of the oxygen atom, resulting in a water molecule having a positive charge on the side of the hydrogen atoms and a negative charge on the side of the oxygen atom. Since opposite electrical charges attract, water molecules tend to attract each other, making water kind of "sticky". The side with the hydrogen atoms (positive charge) attracts the oxygen side (negative charge) of another water molecule. All these water molecules attracting each other means they tend to clump together. This is why water drops are, in fact, drops! If it wasn't for some of Earth's forces, such as gravity, a drop of water would be ball shaped - a perfect sphere. Even if it doesn't form a perfect sphere on Earth, we should be happy water is sticky. Water is called the "universal solvent" because it dissolves more substances than any other liquid. This means that wherever water goes, either through the ground or through our bodies, it takes along valuable chemicals, minerals, and nutrients. pH factor pH is a measure of how acidic or basic water is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH greater than 7 indicates a base. pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water. Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic. Since the pH factor can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically. pH is reported in "logarithmic units", like the Richter Scale, which measures earthquakes. Each number represents a 10-fold change in the acidity or basicness of the water. Water with a pH of 5 is 10 times more acidic than water having a pH of six. Pollution can change a water's pH, which in turn can harm animals and plants living in the water. For instance, water coming out of an abandoned coal mine can have a pH of 2, which is very acidic and would definitely affect any fish living in it! On the logarithm scale, this mine-drainage water would be 100,000 times more acidic than neutral water. Dissolved oxygen
Although water molecules contain an oxygen atom, this oxygen is not what is used by aquatic organisms living in our natural waters. A small amount of oxygen is actually dissolved in water. This oxygen is breathed by fish and zooplankton and is needed by them to survive. Rapidly moving water, such as in a mountain stream or large river, tends to contain a lot of dissolved oxygen, while stagnant water contains little. Bacteria in water can consume oxygen as organic matter decays. Thus, excess organic material in our lakes and rivers can cause an oxygen-deficient situation. Aquatic life can have a hard time in stagnant water that has a lot of rotting, organic material in it, especially in summer, when dissolved-oxygen levels are at a seasonal low. Hardness The amount of dissolved calcium and magnesium in water determines its 'hardness'. If you live in an area where the water is 'soft', then you may never have even heard of water hardness, but if you live in a place where the water is relatively hard, you may notice that it is difficult to get a lather when washing your hands or clothes with soap. And, industries in your area might have to spend money to soften their water, as hard water can damage equipment. Hard water can even shorten the life of fabrics and clothes! Suspended sediment Suspended sediment is the soil moving along a stream. It is highly dependent on the speed of the water flow, as fast-flowing water can pick up and suspend more soil than calm water. During storms, soil is washed from the stream banks into the stream. The amount that washes into a stream depends on the type of land in the river's drainage basin and the vegetation surrounding the river. If land is disturbed along a stream and protection measures are not taken, then excess sediment can harm the water quality of a stream. Sediment coming into a reservoir is always a concern; once it enters, it cannot get out - most of it will settle at the bottom. Reservoirs can "silt in" if too much sediment enters them. The volume of the reservoir is reduced, resulting in less area for boating, fishing, and recreation, as well as reducing the power-generation capability of the power plant in the dam. *********** Fact File *Water covers nearly three-fourths of the Earth's surface. 97% of Earth's water is in the oceans. Only 3% of the Earth's water can be used as drinking water. 75% of the world's fresh water is frozen in the polar ice caps. Over 90% of the world's supply of fresh water is located in Antarctica. *Sources of water pollution include: oil spills, fertilizer and agricultural run-off, sewage and industrial wastes. *Ancient Egyptians treated water by siphoning water out of the top of huge jars after allowing the muddy water from the Nile River to settle. *The Earth's total allotment of water has a volume of about 344 million cubic miles. Of this: 315 million cubic miles (93%) is sea water. 9 million cubic miles (2.5%) is in aquifers (water bearing soil or rocks) deep below the earth's surface. 7 million cubic miles (2%) is frozen in polar ice caps. 53,000 cubic miles of water pass through the planet's lakes and streams. 4,000 cubic miles of water is atmospheric moisture. 3,400 cubic miles of water is locked within the bodies of living things. * It takes two gallons of water to brush your teeth, two to seven gallons to flush a toilet and 25 to 50 gallons to take a shower. * It takes almost 49 gallons of water to produce just one eight-ounce glass of milk. This includes water consumed by the cow, water used to grow the food she eats, plus water used to process the milk. * About 6,800 gallons of water is required to grow a day's food for a family of four. * It takes about one gallon of water to process a quarter pound of hamburger. * Water boils at 2/2 degrees Fahrenheit or 100 degrees Celsius. * Hippocrates, who is known as the father of medicine, directed people in Greece to boil and strain water before drinking it. |
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Politics | Produced by Lake House |
Looking at water, you might think that it's the most simple thing around.
Pure water is colourless, odourless, and tasteless. But it's not at all
simple and plain and is vital for all life on Earth. Where there is water,
there is life, and where water is scarce, life has to struggle. 