Practice Page
Quote: "A river seems a magic thing. A magic, moving, living part of the very earth itself.” Laura Gilpin, US-American photographer, 1891-1979
(Information for Table content:)
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
(end Information Table content)
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')
print "Waiting for dryness..."
while True:
time.sleep(1) # check for dryness every second
if RCtime(18) == 0:
buzz_off(17)
print "Sensor is dry again"
email('dry')
print "Waiting for wetness..."
break
Ende Code-Beispiel
Impressionen:
(Galerie einfügen)
https://upload.wikimedia.org/wikipedia/commons/d/d9/WasserValenz.svg
https://upload.wikimedia.org/wikipedia/commons/d/d3/Proton_Zundel.gif
https://upload.wikimedia.org/wikipedia/commons/0/03/Glacial_iceberg_in_Argentina.jpg
https://upload.wikimedia.org/wikipedia/commons/5/58/Wasser_und_Licht_1.JPG
https://upload.wikimedia.org/wikipedia/commons/5/58/Hydrogen-bonding-in-water-2D.svg
https://upload.wikimedia.org/wikipedia/commons/4/43/Liquid_water_hydrogen_bond.png
Weiterführende Informationen:
https://de.wikipedia.org/wiki/Wasser
(Create new Subpage)
Page "Decision matrix"
Current status: Our marketing department wants to purchase new water bottles as a gift for both our employees worldwide as well as our customers. Choosing the right material for our water bottles is more than picking something shiny and bold. It affects functionality, cost, durability, and customer satisfaction. Plus, if we're going green (which we all should), it's also about environmental impact.
We are planning on selecting vendors based on our findings here beginning of May.
Water bottles
Plastic:
pros: light-weight, affordable, variety, dishwasher-safe
cons: plastic waste, harmful chemicals, retain oders over time, limited insulation
Stainless steel:
pros: durable temperature retention, no harmful chemicals, reusable
cons: heavy, expensive, opaque
Glass:
pros: purity (non-porous), reyclable, aesthetics, no harmful chemicals
cons: fragile, can cause injuries, bad insulation, heavy
Not considered: Aluminum cans, single-use plastic bottles
