Ice is water frozen into the solid state. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions. The addition of other materials such as soil may further alter the appearance.
Ice appears in nature in forms of snowflakes, hail, icicles, glaciers, pack ice, frost, and entire polar ice caps. It is an important component of the global climate, and plays an important role in the water cycle. Furthermore, ice has numerous cultural applications, from ice cooling of drinks to winter sports and the art of ice sculpting.
The molecules in solid ice may be arranged in different ways, called phases, depending on the temperature and pressure. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. The most common phase transition to ice Ih occurs when liquid water is cooled below 0°C (273.15K, 32°F) at standard atmospheric pressure. It can also deposit from vapour with no intervening liquid phase, such as in the formation of frost.
The word is derived from Old English īs, which in turn stems from Proto-Germanic isaz.
Famous quotes containing the word ice:
“Every incident connected with the breaking up of the rivers and ponds and the settling of the weather is particularly interesting to us who live in a climate of so great extremes. When the warmer days come, they who dwell near the river hear the ice crack at night with a startling whoop as loud as artillery, as if its icy fetters were rent from end to end, and within a few days see it rapidly going out. So the alligator comes out of the mud with quakings of the earth.”
—Henry David Thoreau (18171862)
“Suddenly I saw the cold and rook-delighting heaven
That seemed as though ice burned and was but the more ice,”
—William Butler Yeats (18651939)