Good things: Used to generate electricity and drink water.
Bad things: Flooding of fields and crops.
The importance of water:
1. On earth, wherever there is water, there is life. All vital activities come from water.
2. Water in the human body makes up about 65% of body weight. Among them, the brain contains 75% water, blood contains 83% water, muscles contain 76% water, and even hard bones contain 22% water!
3. Without water, nutrients in food cannot be absorbed, waste cannot be excreted, and medications cannot reach the site of action.
4. Once the human body lacks water, the consequences will be very serious. 1-2% dehydration will make you thirsty; 5% dehydration will cause dry mouth, skin wrinkles, confusion and even havisual lucinations; 15% dehydration is often worse than hunger.
5. People can live a long time without food (some estimates are two months). If there is no water, they can live for about a week at most.
Properties of water:
1. Water is a colorless and odorless transparent liquid at normal temperature and pressure. In nature, pure water is rare. Water is usually a solution of acids, alkalis, salts and other substances. This aqueous solution is still called water.
2. Pure water can be obtained by several distillations using platinum or quartz vessels. Of course, this is pure water in a relative sense and cannot be absolutely free of impurities.
3. Water is a substance that can be transformed between liquid, gas and solid states. Solid water is called ice; carbonated water is called water vapor. When the temperature of the water vapor ist greater than 374.2°C, carbonated water cannot be transformed into liquid water by pressurization.