What is the most unique feature of water?

Answer 1

Chemical Properties

• You probably know water is composed of three atoms: one oxygen and two hydrogens. The two hydrogen atoms are on the same side, as seen here. The oxygen is more massive, and needs two electrons to fill its orbit; hydrogen only needs one. As such, the oxygen exerts a stronger pull on the shared electrons than hydrogen does, meaning the shared electrons spend more time with oxygen than they do with hydrogen. The result is a slight positive charge on the hydrogen side, and a slight negative charge on the oxygen side.

Surface Tension

• Because of this slight charge, water is sticky. This is why it can form drops, and why in a glass of water the liquid curves up at the sides. These examples illustrate water's extremely high surface tension, a result of the chemical properties explained above. Simply put, the charges inherent to water cause it to hold together better than most liquids.

Universal Solvent

• Believe it or not, there's no known liquid that can dissolve more than water. This may be a property of water we take for granted while stirring sugar into our tea, but think of this: it's water's propensity for dissolving so many solids that allows it to carry nutrients, minerals and many other substances through your bloodstream. It's also this property that makes water such a powerful geological source---as a river flows it takes along with it valuable minerals and proteins, no small part of what makes the land near rivers so fertile.

Three States

• Water is the only substance found in all three physical states---liquid, solid and gas---naturally at earth temperatures. All three states are, in nature, essential ways of water moving, flowing or being stored. The water cycle involves rain falling, being used by plants and eventually evaporating again to fall somewhere else. Also, frozen water in the form of snow in the mountains is a major source of water for rivers everywhere on earth. The interplay of water switching among its three states is vitally important to life on Earth.

Holds heat

• Water can adsorb a lot of heat before it gets hot, and releases that heat very slowly. It is for this reason that lakes and oceans have such a profound impact on weather. Travel to Nova Scotia, Canada, during the spring, and cold temperatures linger for a long time---a result of the cold water in the north Atlantic regulating the temperatures. Buffalo, New York, tends to get hammered with snow because clouds blowing over the Great Lakes are cooled by the cold water. Inversely, the area of Seattle Washington is much warmer than its longitude would suggest, the result of nearby warm ocean currents.

Answer 2

Water's most unique feature is its ability to exist in all three states of matter (liquid, solid, gas) naturally on Earth. This property allows water to support life as we know it and also makes it an excellent solvent for a wide range of substances.