Earth's Water Basics
Water is the most essiential substance. Every living thing's life depends on it. Almost all the water on Earth is in the oceans but 2.4% is on land and in the atmosphere. 50%-90% of the weight of living organisms is all water making it very important for the water to be replenished. Although a human can go 5-7 days.
Water is a compound made of hydrogen and oxygen. It can exist in three states; liquid, water vapor, and ice. Water forms many of the things in the world, like glaciers, clouds, lakes and many more. Water can turn into a solid at any temperature under 32 degrees and it will turn to a vapor at temperatures over 212 degrees. The chemical formula for water is H2O; 2 hydrogen atoms and 1 oxygen atom. Humidity is the amount of water in the air. When the humidity is higher there is a better chance of it precipitating.
Some water is clean drinking water and other water can be filled with dangerous chemicals. The quality of the water depends on where it comes from. Water that goes to your house that you use for drinking, bathing, washing clothes, etc. gets treated before it gets used. Although some people still get viruses, bacteria and un-organic things in their water. The quality of your water depends on the local geology, ecosystems, sewage, and industrial pollution. The Unites States Agency (EPA) limits the amount of contaminant's in the tap water in the US. The water you find in streams, lakes, ponds and oceans is likely contaminated. The world is made up of about 70% water but only 2.5% is fresh drinkable water and 1% of the water is accessible to humans. Almost all of the earths water is saltwater. 97% of the water on earth is saltwater which is water filled with salt and other minerals that come from the ocean. 2% of the earths water is in glaciers at the north and south poles. Eventually all the water in the glaciers will melt and become usable.