Things having something to do with water may have "hydro" or "aqua" in their name, such as hydropower or aquarium, from the Greek and Latin names for water. It is also called the "universal solvent", because it dissolves many other compounds.
In small amounts, water appears to have no colour but in large amounts (such as seas or lakes), it has a very light blue color.
Plants and animals (including people) are mostly water inside, and must drink water to live. It gives a medium for chemical reactions to take place, and is the main part of blood. It keeps the body temperature the same by sweating from the skin. Water helps blood carry nutrients from the stomach to all parts of the body to keep the body alive. Water also helps the blood carry oxygen from the lungs to the body. Saliva, which helps animals and people digest food, is mostly water. Water helps make urine. Urine helps remove bad chemicals from the body. The human body is between 60% and 70% water, but this value differs with age; i.e. a foetus is 95% water inside.
Water is the main component of drinks like milk, juice, and wine. Each type of drink also has other things that add flavor or nutrients, things like sugar, fruit, and sometimes alcohol. Water that a person can drink is called "potable water" (or "drinking water"). The water in oceans is salt water, but lakes and rivers usually have unsalted water. Only about 3% of all the water on earth is fresh water. The rest is salt water.
Many places, including cities and deserts, don't have as much water as people want. They build aqueducts to bring water there.
Though people can survive a few months without food, they can only survive for a day or two without water. A few desert animals can get enough water from their food, but the others must drink.
Water has no smell,taste or color
Water is also used for recreational purposes, "see list of water sports".
Water is used as both the coolant and the neutron moderator in most nuclear reactors. This may be ordinary water (called light water in the nuclear industry) or heavy water.
Water is also used for washing a lot of objects. Goods, services and people are transported to other countries in watercrafts on bodies of water.
Water is used in chemical reactions as a solvent or reactant. Water is also used in fire fighting. Water is also used for cooking.
The dihydrogen monoxide parody involves calling water by the unfamiliar chemical name "dihydrogen monoxide" (DHMO) and listing some of its harmful effects in an alarming way. Some examples include talking about how "it causes burning, suffocation and corrosion," when it is actually just talking about hot water, drowning and rust. Sometimes the parody calls for it to be banned and/or labelled as dangerous.
The prank works because it takes advantage of people's misunderstanding. Calling water by an unfamiliar name and making it sound like a harmful chemical can make people think it is dangerous.
"Dihydrogen monoxide" is an alternative chemical name for water, but nobody uses it. The word "dihydrogen" means two hydrogens, and "monoxide" means one oxygen. The chemical formula of water has two hydrogens and one oxygen.
The parody gained most of its popularity in the 1990s, when a 14-year-old named Nathan Zohner collected anti-DHMO petitions for a science project about gullibility. Zohner fooled a lot of people, which has led to his project being used in lessons about critical thinking and the scientific method.
The website DHMO.org is a joke website which lists the harmful effects of water (DHMO), answers questions, and calls for it to be banned, among other things.
A BBC short item explains that every molecule on Earth has existed for billions of years, and all of them came from elsewhere. Water is alien because it arrived on asteroids and comets. It is the second most common molecule in the universe. Why is it not a gas? It is made of two very light elements. Ice floating on water is also an oddity. Also, hot water freezes faster than cold, and no-one knows why this is. Molecules of water can move up against the force of gravity (that is due to surface adhesion).
Much of the universe's water is produced as a by-product of star formation.
On 22 July 2011, a report described the discovery of a gigantic cloud of water vapor containing "140 trillion times more water than all of Earth's oceans combined" around a quasar located 12 billion light years from Earth. According to the researchers, the "discovery shows that water has been prevalent in the universe for nearly its entire existence".
Water has been detected in interstellar clouds in our galaxy, the Milky Way. Water probably exists in abundance in other galaxies, too. Its components, hydrogen and oxygen, are among the most abundant elements in the universe. Most other planetary systems are likely to have similar ingredients.
We do not know exactly how the Earth came to have so much water. It is everywhere in the Universe, but rarely in such quantity. Reasoning from first principles, every element except hydrogen has been formed in stars. Therefore oxygen was originally formed in stars. The formation of water is not a problem: it is exothermic, so forming the molecule from its atoms does not need outside energy. But to explain how the Earth has so much in comparison with, for example, Mars, is not easy. It is an undecided problem in planetary geology.
It was long thought that Earth’s water did not come from the planet’s region of the protoplanetary disk. Instead, it was thought that water and other volatiles must have been delivered to Earth from the outer Solar System later in its history. But hydrogen inside the Earth did play some role in the formation of the ocean. The two ideas may each be partly right. Water was delivered to Earth by impacts from icy planetesimals (asteroids) in the outer edges of the asteroid belt. How much is not known.
Water vapor is found in:
Liquid water is found on Earth. It covers about 71% of the surface of the Earth. Liquid water is sometimes found in small amounts on Mars. Scientists believe that liquid water is in Enceladus, Titan, Europa and Ganymede.
Water ice is found in:
Want
A want is a wish or a desire for something. If a person would like to have something, but can choose not to have it, that thing is wanted or can be called a want. To want is not the same as to need, which is when someone "must" have something.
People often talk about needing a thing, when they really just want it. Wants can be for the same things as needs. For example, a person can "need" to eat food and can "want" to eat cake. If there is no cake then he or she may have to eat something else, perhaps bread. The need is no longer so important (the person is no longer hungry) although the want may still be there. If there is cake, then the person's needs and wants can both be met.
In economics, a want is about goods or services. Choice is how to satisfy a want, when there are different ways to do this.
Want can also be the idea of what it means to be poor, hungry or with no money. Charles Dickens wrote a famous book called "A Christmas Carol" in which there are two children, named Want and Ignorance.War
War is a situation or a period of fighting between countries or groups of people. A war generally involves the use of weapons, a military organization and soldiers. War is a situation in which a nation enforces its rights by using force. Not every armed conflict is a war. A fight between individuals, between gangs, drug cartels, etc. is not considered a war. However, most wars are called armed conflicts. International humanitarian law is a set of rules that tries to limit the effects of wars. International Humanitarian Law recognizes two kinds of wars. These are: