Water

Water is an inorganic compound with the chemical formula H₂O. It is clear, has no taste, smell, and is almost colorless. Water is everywhere on Earth. It makes up most of our streams, lakes, and oceans, and it is inside all living things. Because it can dissolve many different things, water is often called the “universal solvent.”

On Earth, water can be a solid, a liquid, or a gas. We see it as rain, snow, fog, and steam. It is always moving through the water cycle of evaporation, condensation, precipitation, and runoff. This movement helps shape our planet and supports all life.

Water is very important for our daily lives. Most fresh water that people use helps grow plants, and many people depend on fishing in salt and fresh water for food. We also use water for cooling, heating, cooking, cleaning, and fun activities like swimming, surfing, ice skating, and skiing.

Etymology

The word water comes from Old English wæter. It is related to words in many other languages. In Dutch it is water, in German it is Wasser, and in Russian it is вода́ (vodá). All these words have a common ancient root meaning 'water' or 'wet'.

History

Main articles: Origin of water on Earth § History of water on Earth, and Properties of water § History

Water has been very important to our planet for a long time. Scientists study how water first came to Earth. They also study how water has changed over millions of years. They look at the special qualities of water that make it necessary for life.

Properties

Main article: Properties of water

See also: Water (data page) and Water model

Water (H₂O) is a special kind of substance called an inorganic compound. At normal room temperature, it is a liquid that has no taste or smell. It looks almost clear, with just a tiny bit of blue color. Water is very important because it can dissolve many other things. This is why it is called the “solvent of life.” Water can be a solid (ice), a liquid, or a gas (water vapor).

Water changes with temperature and pressure. When it gets cold, it freezes into ice. When it gets warm, it turns into vapor or steam. These changes are called phase transitions. One interesting fact about water is that it becomes less thick as it cools down. Ice is less thick than liquid water. This is why ice floats in water and why lakes don’t freeze completely in winter — the ice on top keeps the water below safe.

On Earth

Water is found everywhere on Earth, in oceans, lakes, rivers, and even in the air. Scientists study how water moves and changes. This includes learning about water under the ground, glaciers, and the oceans. All the water on Earth is called the hydrosphere, and there is a lot of it.

Water moves through a process called the water cycle. It evaporates from oceans and plants release it into the air. Then, it falls back to Earth as rain, snow, or hail. This cycle helps shape our lands over time.

Water is very important for life and the environment. People use water for drinking and growing food. Most of Earth's fresh water is stored in glaciers, while some is underground or in lakes and rivers. Seawater makes up most of the ocean and has salts that change how it freezes. Tides—the rising and falling of ocean levels—are caused by the pull of the Moon and the Sun on Earth's waters.

Effects on life

Water is very important for all living things. It helps our bodies do many things, like turning food into energy and building our bodies. Without water, these things could not happen.

Many animals and plants live in water. Fish breathe through gills, while animals like dolphins and whales need to come up for air. Plants like kelp and algae grow in the ocean, and they are important for many animals that eat them. Water is where life first began, and it still helps many different kinds of creatures.

Further information: Hydrobiology, Marine life, and Aquatic plant

Effects on human civilization

Civilization has grown up around rivers and big water ways. Ancient societies like Mesopotamia and Egypt depended on rivers such as the Tigris, Euphrates, and Nile to survive. Today, large cities like Rotterdam, London, New York City, and Tokyo are successful partly because they have water for trade and travel.

Water is important for our health and daily life. We use it for drinking, cooking, and cleaning. Clean drinking water, called drinking water, helps keep us healthy. Water is also important for farming, making things, and creating energy. It is a very important resource for life and work.

Distribution in nature

Water is found everywhere in the universe. It forms when stars are born, and big clouds of water vapor have been seen far from Earth. We can also find water in the air around stars, planets, and moons.

On Earth, water is usually a liquid and covers most of our planet. It can also be found as ice on Earth, the Moon, Mars, and many other places in space. Water is very important for life as we know it.

Law, politics, and crisis

Water politics is how water affects choices and disagreements between countries and groups. Fresh water is very important, and people need it to live. Some places still don’t have enough clean water or good ways to keep it clean.

More people now have access to clean water, but millions still don’t have enough. Some experts think that by 2025, water problems will affect most of the world’s people. Good rules and careful planning are needed to make sure everyone has enough water and to protect rivers, lakes, and oceans.

In culture

Religion

See also: Sacred waters

Water is considered a purifier in many religions. Faiths that use ritual washing include Christianity, Hinduism, Islam, Judaism, the Rastafari movement, Shinto, Taoism, and Wicca. In Christianity, being immersed in water is an important part of the sacrament of baptism. In Islam, washing parts of the body with clean water is done before prayers. In Shinto, water is used in rituals to cleanse people or places.

Philosophy

The Ancient Greek philosopher Empedocles thought water was one of the four basic elements of the universe. Thales believed that everything is made from water. In traditional Chinese philosophy, water is one of the five elements and is seen as a symbol of softness and strength.

Folklore

In many folktales, “living water” has magical powers, such as healing or helping people. The idea of magical waters also appears in stories like the Fountain of Youth.

Art and activism

The modern novel Ulysses by James Joyce has a passage called the “water hymn,” which celebrates water. Artists have also shown the importance of water through exhibitions and projects, showing how valuable water is to our lives.

Dihydrogen monoxide parody

Main article: Dihydrogen monoxide parody

Sometimes, water is called “dihydrogen monoxide” as a joke to make fun of people who don’t understand science. This name has been used in hoaxes to make people worried about water, which is actually safe and essential for life.

Music

The word “Water” is used by some Florida-based rappers as a catchphrase. Some have even made songs about the water in Florida.