Water is an inorganic compound with the chemical formula H2O. It is a transparent, tasteless, odorless, [c] and nearly colorless chemical substance. It is the main constituent of Earth's streams, lakes, and …

Jun 8, 2026 · Water, substance composed of the chemical elements hydrogen and oxygen and existing in gaseous, liquid, and solid states. It is one of the most plentiful of compounds and has the …

Within the Earth's atmosphere and surface, the liquid phase is the most common and is the form that is generally denoted by the word "water". The solid phase of water is known as ice and commonly …

Welcome to the science section of the USGS Water Science School, where you can explore the many aspects of water. All of our information is available by browsing the various categories below.

Water | H2O | CID 962 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards ...

Jan 28, 2026 · Not only does water make up most of your weight, it’s involved in many important functions. See how water improves your overall well-being.

All living things, from tiny cyanobacteria to giant blue whales , need water to survive. Without water, life as we know it would not exist. And life exists wherever there is water

Jun 8, 2026 · Water cycle, cycle that involves the continuous circulation of water in the Earth-atmosphere system. Of the many processes involved in the water cycle, the most important are …

Dec 23, 2025 · Water is in constant movement across our planet. The water cycle shapes our weather and climate patterns & provides freshwater that supports all life on Earth.Observing and monitoring …

Jan 21, 2026 · How much water should you drink each day? It's a simple question with no easy answer. Studies have recommended drinking different amounts over the years. But how much water a body …