Phases of Matter VIII - The Wonder of Water 1
Written by Translator on June 30, 2008 – 9:41 pm -Crossposted at Dailykos.com
None of us should be alive. We are only because of water. Water. Everyone knows about it, everyone uses it, but few understand it. Every schoolchild knows that water is H20, but few scientists realize the ramifications of that simple formula.
Water has a molecular weight of 18 atomic mass units (amu, the mass of a proton or neutron, roughly) since the common isotope of oxygen has a a mass of 16 amu, and that of the most common type of hydrogen has a mass of one amu.
Water looks sort of like Mickey Mouse, in that the two hydrogen atoms make an angle through the H-O-H bond of about 104.45 degrees.
Water, at 18 amu, should be a gas. Nothing with that molecular weight is a solid except for lithium, and it is a metal, and metallic bonds are special. I wrote about that earlier in this series.
All of the atmospheric gases weight more, on a molecular basis, than water. Ammonia, water’s close cousin, is a gas at STP (standard temperature and pressure, one atmosphere at 20 degrees C). Both ammonia and water share a special property, but water does it better.
The secret is the hydrogen bond. It turns out, due to both electrostatic and quantum mechanical considerations, that hydrogen (the lightest and smallest element) when bonded to nitrogen, oxygen, or fluorine (the most electron hungry elements in the second row of the periodic table) is “special”.
We should all be dead, and water should not exist. But the hydrogen bond changes everything. More in future, if any interest. I will hang around a bit to answer comments and stave off flames. Warmest regards, Doc.
Tags: Hydrogen bonds, Phases of matter, Quantum Mechanics, Teaching, Water
Posted in Science |
3 Comments
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We humans are all 50+ percent water, some much more and some on par, none less. It’s the dividing line between life and death.
Think about it, you must take in a certain amount of water a day or die. People in Southern hotter states much more than people in Northern cooler states, make your choice and drink your water!
More like 75% plus. There was an episode on “Star Trek: The Next Generation” wherein the natives of the planet, when found to be sentient, called humans “ugly bags of mostly water”. I can not improve on that description, although I will back off of the “ugly” part. But we are pretty much bags of water. Warmest regards, and thank you not only for reading, but for taking the time to make a comment. Warmest regards, Doc.
Doc,
The hydrogen bond is fascinating! More on that please. I remember the STTNG episode, may have that in my video files ;-). Being a massage therapist, it’s hard to say what we are. I work on muscles-tendons-ligaments to relax bones and brains and give my clients water after! (Both the human and animal kind)