Author Topic: What is WATER?  (Read 7944 times)

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What is WATER?
« on: September 12, 2008, 16:54:17 pm »
Well,

New topic and i think it can be a good one!

Here is a picture of water!
And the website where it came from:   http://focus.aps.org/story/v19/st19

At any given moment, each oxygen atom is typically surrounded by four hydrogens--two close ones from its own molecule, and two further away on nearby molecules. At the same time, within each molecule, the oxygen has a bit more negative charge, and the hydrogens are a bit more positive--a charge separation called a dipole.

If you apply an electric field to water, you expect the molecules to align their dipoles along the field lines, on average, like so many compass needles aligning in Earth's magnetic field. The degree to which they align with and augment the electric field is called polarizability. But in the hydrogen-bonded network of water, the dipoles are already partially aligned with each other, even before you apply the field. Clusters of nearby molecules act as a single, larger dipole, enhancing the field more than they would on their own. This so-called collective effect is one reason for water's large polarizability. But researchers have wondered how this effect compares with a second one: Each oxygen pulls the hydrogens further from the oxygen in neighboring molecules, which increases the charge separation within each molecule and therefore the strength of each molecule's individual dipole.
The uncertainty about which effect is bigger arises because the electrons are spread out among the molecules. Calculations and experiments show how the charge varies from place to place, but there is no easy way to assign each bit of charge to a particular molecule. Only in the last decade have physicists perfected mathematical methods to make definitive assignments of charges.

Manu Sharma of the University of California at Davis and his colleagues have now applied the new techniques to water and definitively determined the contributions of the two effects to water's large polarizability. The team first simulated a few dozen water molecules using only basic laws of physics. To assess the effect of individual molecular dipoles, they computed the dipole for each molecule and found values that were typically 60% bigger than for water vapor, where the molecules don't interact. To measure the collective effect, they monitored how often the alignments of nearby molecules changed together, and found that collective motions more than doubled the polarization. Both effects contributed to the large polarizability they calculated--a value that agrees well with experiments.

Accounting for individual dipoles also showed that almost all of the collective enhancement comes from neighboring molecules, rather than those further away. Since more distant molecules are unimportant, the strong polarizability should persist even when water is confined in very tight spaces, for example in proteins and other biological molecules. Biophysicists have assumed as much, when modeling the atomic-scale functioning of biomolecules, but these results provide solid evidence.

David Vanderbilt of Rutgers University in New Jersey helped establish the charge accounting scheme. He says that calculating the right polarizability--and the closely related dielectric constant--and disentangling the various contributions is "a kind of milestone" for first-principles theory. "The dielectric constant of liquid water is a complicated thing."



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Steve

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Re: What is WATER?
« Reply #1 on: September 12, 2008, 17:23:08 pm »
More facts:

The hydrogen bonds that give water its strength also are responsible for many unique and important properties of water. Most substances contract when they solidify, but water expands, and, thus, becomes lighter. Ice is less dense than liquid water because more hydrogen bonds are intact, and water molecules aligned by hydrogen bonding occupy more space. Thus, when water freezes it becomes so strong it can break pipes and rocks! If water behaved like most substances, lakes would freeze from the bottom, and life would be tough for aquatic creatures. Another unusual property of water is that much more energy is needed to heat it than is needed to warm most things. It is hard to heat water because molecules must vibrate more vigorously to become warmer, but hydrogen bonds restrict the movement of water molecules.

More odd stuff:
Current theories led us to believe that the detergent compound SDS acted to produce an electric field around itself by simply orienting neighbouring water molecules without significantly changing the normal properties of water. Thus, it was thought that the molecules aligned themselves with the applied electric field just as a compass needle does in the magnetic field of the Earth. This phenomenon is known as water polarization and is well known by scientists, having important implications for biological and chemical processes related with electrical interactions in water: interaction between membranes, the formation of films and foams, and colloidal stability, among others.

However, the results obtained by this research show that, under certain circumstances, water prefers to behave in a completely abnormal way and to organize itself. In prime films formed by water and SDS (such as those found in foam and bubbles), water molecules are immobilized and cluster together forming special structures, about three molecules thick, around the SDS molecules. Behaving in this way, water manages to completely cancel out the electric field created by the detergent and even to invert it. Hence, to the contrary of what was thought up to now, the action of these detergent chemical compounds is determined mainly by how far water molecules “tolerate” or oppose their presence.


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Steve

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Re: What is WATER?
« Reply #2 on: September 14, 2008, 10:25:36 am »
Its getting more and more interesting, is it... ;)
So strange how water works..

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Re: What is WATER?
« Reply #3 on: September 15, 2008, 00:16:49 am »
New info:

The hydrogen bond in water is part (about 90%) electrostatic and part (about 10%) covalent .... ;)

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Re: What is WATER?
« Reply #4 on: September 15, 2008, 22:17:27 pm »
Hi H2O,

90% Static and 10% covalent.
What does that mean? What is covalent and what is static?  What kind of conductor or technic can we make/create to get a static force.
It doesnt say anything about the amount of energy of the force. Lets find that out as well.
With no money in the pocket, we can do what we can and that is research on the NET.

We are getting closer to the truth... :D

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Steve

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Re: What is WATER?
« Reply #5 on: September 15, 2008, 22:43:41 pm »
Ok, answers:

Static Electricity is defined as an electrical charge caused by an imbalance of electrons on the surface of a material. This imbalance causes an electric field that can be measured and that can influence other objects at a distance.

More:
When two objects in each other's vicinity have different electrical charges, an electrostatic field exists between them. An electrostatic field also forms around any single object that is electrically charged with respect to its environment. An object is negatively charged (-) if it has an excess of electrons relative to itssurroundings. An object is positively charged (+) if it is deficient in electrons with respect to its surroundings.

Electrostatic fields bear some similarity to magneticfields. Objects attract if their charges are of opposite polarity (+/-);objects repel if their charges are of the same polarity (+/+ or -/-). The lines of electrostatic flux in the vicinity of a pair of oppositely charged objects are similar to lines of magneticflux between and around a pair of opposite magnetic poles. Inother ways, electrostatic and magnetic fields differ. Electrostatic fields areblocked by metallic objects, while magnetic fields can pass through most (but not all) metals. Electrostatic fields arise from a potential difference or voltage gradient, and can exist when charge carriers, such as electrons, are stationary (hence the "static"in "electrostatic"). Magnetic fields arise from the movementof charge carriers, that is, from the flow of current.

When charge carriers are accelerated (as opposed to movingat constant velocity), a fluctuating magnetic field is produced. This gives rise to a fluctuating electric field, which in turn produces another varying magnetic field. The result is a "leapfrog" effect, in which both fields canpropagate over vast distances through space. Such a synergistic field is known as an electromagnetic field, and is the phenomenon that makes wireless communications, broadcasting, and control systems possible.




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steve

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Re: What is WATER?
« Reply #6 on: September 15, 2008, 22:47:12 pm »
So, what is electrostatic charge?

In physics, charge, also known as electric charge, electrical charge, or electrostatic charge and symbolized q, is a characteristic of a unit of matter that expresses the extent to which it has more or fewer electrons than protons. In atoms, the electron carries a negative elementary or unit charge; the proton carries a positive charge. The two types of charge are equal and opposite.
In an atom of matter, an electrical charge occurs whenever the number of protons in the nucleus differs from the number of electrons surrounding that nucleus. If there are more electrons than protons, the atom has a negative charge. If there are fewer electrons than protons, the atom has a positive charge. The amount of charge carried by an atom is always a multiple of the elementary charge, that is, the charge carried by a single electron or a single proton. A particle, atom, or object with negative charge is said to have negative electric polarity; a particle, atom, or object with positive charge is said to have positive electric polarity.

In an object comprised of many atoms, the net charge is equal to the arithmetic sum, taking polarity into account, of the charges of all the atoms taken together. In a massive sample, this can amount to a considerable quantity of elementary charges. The unit of electrical charge in the International System of Units is the coulomb (symbolized C), where 1 C is equal to approximately 6.24 x 1018 elementary charges. It is not unusual for real-world objects to hold charges of many coulombs.

An electric field, also called an electrical field or an electrostatic field, surrounds any object that has charge. The electric field strength at any given distance from an object is directly proportional to the amount of charge on the object. Near any object having a fixed electric charge, the electric field strength diminishes in proportion to the square of the distance from the object (that is, it obeys the inverse square law).

When two objects having electric charge are brought into each other's vicinity, an electrostatic force is manifested between them. (This force is not to be confused with electromotive force, also known as voltage.) If the electric charges are of the same polarity, the electrostatic force is repulsive. If the electric charges are of opposite polarity, the electrostatic force is attractive. In free space (a vacuum), if the charges on the two nearby objects in coulombs are q1 and q2 and the centers of the objects are separated by a distance r in meters, the net force F between the objects, in newtons, is given by the following formula:

F = (q1q2) / (4or2)

where o is the permittivity of free space, a physical constant, and  is the ratio of a circle's circumference to its diameter, a dimensionless mathematical constant. A positive net force is repulsive, and a negative net force is attractive. This relation is known as Coulomb's law


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steve

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Re: What is WATER?
« Reply #7 on: September 15, 2008, 22:58:57 pm »
More!

Even though electrostatically induced forces seem to be rather weak, the electrostatic force between e.g an electron and a proton, that together make up a hydrogen atom, is about 40 orders of magnitude stronger than the gravitational force acting between them.

steve