section_path: Water on Earth
section_name: Water on Earth
paragraph_text: Water on Earth
  
  Water is a chemical substance that is composed of hydrogen and oxygen (H2O) and is vital for all known forms of life. In typical usage, "water" refers only to its liquid form, but it also has a solid state, ice, and a gaseous state, water vapor, or steam. Water covers 71% of the Earth 's surface. On Earth, it is found mostly in oceans and other large bodies of water, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds, and precipitation. Oceans hold 97% of surface water, glaciers, and polar ice caps 2.4%, and other land surface water such as rivers, lakes, and ponds 0.6%. Additionally, a minute amount of the Earth's water is contained within biological bodies and manufactured products.