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 …

Apr 30, 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 …

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.

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. All organisms, like animals and …

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 …

Jun 10, 2025 · Water is the most abundant molecule on Earth, but there are many facts about this substance you probably don't know.

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

Water is a common chemical substance that is essential for all known forms of life. [1] In typical usage, the term water refers to its liquid state, but the substance also has a solid state, ice, and a gaseous …

Mar 13, 2026 · Learn about EPA's work to protect and study national waters and supply systems. Subtopics include drinking water, water quality and monitoring, infrastructure and resilience.

Jul 25, 2018 · What is Water? Water vapor condenses in the atmosphere and fall to the ground as rain. Water is an odorless, almost colorless, tasteless and transparent abundant chemical compound …