Water A Remarkable Molecule

Water is easily the most common and important liquid on Earth. It fills our oceans, lakes, and streams. In its solid form, it covers nearly an entire continent (Antarctica), as well as large regions around the North Pole, and caps mu tallest mountains. In its gaseous form, it humidifies our air. We drink water, we sweat water, and we excrete bodily wastes dissolved in water. Indeed, the majority of our body mass is water. Life is impossible without water, and in most places on Earth where liquid water exists, life exists. Recent evidence of water on Mars— that existed either in the past or exists in the present— has fueled hopes of finding life or evidence of life there. Water is remarkable. 

The Environmental Protection Agency (EPA), under the Safe Drinking Water Act of 1974 and its amendments, sets standards that specify the maximum contamination level (MCL) for nearly 100 biological and chemical contaminants in water. Water providers that serve more than 25 people must periodically test the water they deliver to their consumers for these contaminants. If levels exceed the standards set by the EPA, the water provider must notify the consumer and take appropriate measures to remove the contaminant from the water. According to the EPA, if water 

A Safe drinking water has a major effect on public health and the spread of disease. In many parts of the world, the water supply is unsafe to drink. In the United States the Environmental Protection Agency (EPA) is charged with maintaining water safety. 

CAN YOU ANSWER THIS Suppose a sample of water is contaminated by a nonvolatile contaminant such as lead. Why doesn t boiling eliminate the contaminant  

Properties of Liquids Common liquids include water, acetone (fingernail-polish remover), and rubbing alcohol. Water is the most common and most important liquid on Earth. It is difficult to imagine life without water. 

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