Water fit for human consumption is called drinking water or potable water. Water that is not potable may be made potable by filtration or distillation, or by a range of other methods. More than 660 million people do not have access to safe drinking water. [108] [109]

absorbed from air or water) to form glucose and release oxygen. [107] All living cells use such fuels and oxidize the hydrogen and carbon to capture the sun's energy and reform water and COWaterfalls are also classified by height. Angel Falls, the world’s tallest waterfall, plummets 979 meters (3,212 feet) into a remote canyon in a rain forest in Venezuela. The water, from the Gauja River, often does not reach the bottom. The fall is so long, and so steep, that air pressure is stronger often than the water pressure of the falls. The water is turned to mist before it reaches the small tributary below.

Another popular way of classifying waterfalls is by width. One of the widest waterfalls is Khone Phapheng Falls, Laos. At the Khone Phapheng Falls, the Mekong River flows through a succession of relatively shallow rapids. The width of the Khone Phapheng Falls is about 10,783 meters (35,376 feet). The collective mass of water found on, under, and over the surface of a planet is called the hydrosphere. Earth's approximate water volume (the total water supply of the world) is 1.386 billion cubic kilometres (333 million cubic miles). [24]The viscosity of water is about 10 −3 Pa· s or 0.01 poise at 20 °C (68 °F), and the speed of sound in liquid water ranges between 1,400 and 1,540 meters per second (4,600 and 5,100 ft/s) depending on temperature. Sound travels long distances in water with little attenuation, especially at low frequencies (roughly 0.03 dB/km for 1 k Hz), a property that is exploited by cetaceans and humans for communication and environment sensing ( sonar). [100] Reactivity Mineral deposits in water can reduce the effectiveness of your water flosser over time, particularly if you live in a hard-water area.

Liquid water is found in bodies of water, such as an ocean, sea, lake, river, stream, canal, pond, or puddle. The majority of water on Earth is seawater. Water is also present in the atmosphere in solid, liquid, and vapor states. It also exists as groundwater in aquifers.Niagara and many other falls with large volumes of water are used to generate hydroelectric power. A tremendous volume of water flows over Niagara Falls, as much as 5,525 cubic meters (195,000 cubic feet) per second. Power stations upstream from the falls convert hydroelectric energy into electricity for residential and commercial use. A chute is a waterfall in which the stream passage is very narrow, forcing water through at unusually high pressure. Three Chute Falls is named for the three "chutes" through which the Tenaya Creek falls in Yosemite National Park, California, U.S. Fan waterfalls are named for their shape. Water spreads out horizontally as it descends. Virgin Falls is a striking fan waterfall on Tofino Creek, on Vancouver Island, British Columbia, Canada.