Practice Page/Unformatted Wiki Page Water: Difference between revisions

Revision as of 13:52, 28 November 2025

Quote: "A river seems a magic thing. A magic, moving, living part of the very earth itself.” Laura Gilpin, US-American photographer, 1891-1979

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Chemical Structure Formula

General Information Name: Water Molecular Formula: H2O Appearance: almost colorless or white crystalline solid, almost colorless liquid, with a hint of blue, colorless gas

Identifiers CAS Number: 7732-18-5

Properties Molar Mass: 18.01528(33) g/mol Density: Liquid

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Introduction: Water is an inorganic compound with the chemical formula H2O. It is a transparent, tasteless, odorless, and nearly colorless chemical substance, and it is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. In liquid form, H2O is also called "Water" at standard temperature and pressure. Because Earth's environment is relatively close to water's triple point, water exists on Earth as a solid, a liquid, and a gas. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water covers about 71% of the Earth's surface, with seas and oceans making up most of the water volume (about 96.5%). Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor, clouds (consisting of ice and liquid water suspended in air), and precipitation (0.001%). Water moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea.

Etymology: The word water comes from Old English wæter, from Proto-Germanic *watar (source also of Old Saxon watar, Old Frisian wetir, Dutch water, Old High German wazzar, German Wasser, vatn, Gothic 𐍅𐌰𐍄𐍉 (wato)), from Proto-Indo-European *wod-or, suffixed form of root *wed- ('water'; 'wet').

On Earth: Hydrology is the study of the movement, distribution, and quality of water throughout the Earth. The study of the distribution of water is hydrography. The study of the distribution and movement of groundwater is hydrogeology, of glaciers is glaciology, of inland waters is limnology and distribution of oceans is oceanography. Ecological processes with hydrology are in the focus of ecohydrology. The collective mass of water found on, under, and over the surface of a planet is called the hydrosphere. Earth's approximate water volume (the total water supply of the world) is 1.386 billion cubic kilometres (333 million cubic miles).

Poetry:Water appears as one of the leading symbols in oral and written literature since the beginning of history. As a must-have life source, water penetrates into literary works with a variety of symbolism. Into the sunshine, Full of the light, Leaping and flashing, From morn till night! Into the moonlight, Whiter than snow, Waving so flower- like When the winds blow! Into the starlight, Rushing in spray, Happy at midnight, Happy by day! James Russell Lowell (1819-1891)

Chemical Equation: The reaction of hydrogen and oxygen produces water.

2H2 + O2 -> 2H2O

Evaporation of a Saline Solution

(drawio-diagramm)

Raspberry Pi Wassersensor: This is a code snippet to program a moisture sensor (in Python):

Start Code-Beispiel

while True:

time.sleep(1) # check for wetness every second

if RCtime(18) == 1:

buzz_on(17)

print "Sensor is wet"

email('wet')