Posted: Sun Oct 07, 2007 2:45 pm Post subject: The wonderful world of water
The wonderful world of water
Here are a few facts you may have not known about H20
Of course you know that water can exist in three (mainly) forms…
Solid
Liquid
Gas
With just a small rise or fall in temperature it will turn into either a solid or a gas. Everyone knows this…
These changes such as liquid to solid, liquid to vapor (Water evaporates at ALL temperature) have extraordinary “tempering” effects that we normally forget or may not even know about.
When temperature falls water will become ice. So what?
When Ice melts it needs tons of heat to do it. So what?
Remember that rule, the one that says, “Energy can nether be created or destroyed”?
Well, let’s take a look at the water (or ice) and how heat is involved in thawing and freezing.
Freezing is what happens when HEAT is displaced or ‘moved’. You see when water freezes HEAT is let out. The heat in the water is released and only the slow or ‘cold’ molecules remain in the water witch will eventually turn into ice.
Well what about thawing ice? It is the process of heat being absorbing into the ice is namely, ‘thawing’. If you were to thaw one pound of water, you would use X amount of energy. That X amount of energy would HAVE TO be taken out of the one pound of water to reform it to ice.
Let me explain just a little more, the heat given out by the freezing water will actually slow the freezing process; this tends to slow down the temperature change in the vicinity of the water. Think of this, in areas of great water, such as ponds, lakes and rivers, gives tremendous amounts of energy when the temperature becomes cold. This energy given out by those bodies of water keeps the temperature in those areas from reaching extreme bitter cold temperature. Think of North Dakota and its tremendously bitter cold temperature and no large bodies of water and then of Michigan’s witch is at the same latitude, but has the great lakes surrounding it. It has much nicer and milder temperature during winter time.
Now let’s explore another aspect of water. Lets take water at normal temperature (lets say 70 degrees), if the temperature were to fall at the surface, the colder water (not ice yet) at the top would sink to the bottom, as it contracts and gets denser. The wormer water from the bottom will be forced up because of it being lighter and less dense then the falling cold water. This becomes a cycle that will continue until water comes to exactly 39 degrees. When this point happens, that cycle will stop and the water will be at its greatest density. When the temperature continues to fall more, the water will begin to expand (even form something similar to a crystal) this means the expanded water will then make its way to the top (less dense) to form ice. In most cases the ice that forms on top of the water will act like a wall to prevent the farther freezing to the water under the ice. Ice is a poor conductor of heat and the denser water underneath the ice will remain near the constant 39 degrees.
Because water is so different then other liquids it makes life possible. Think if the ice were to sink (or act like 99% of all other liquids) it would freeze rivers lakes oceans solid and kill everything (maybe except microorganisms); it would most likely render earth inhabitable.
Let’s talk about the vapor now.
Clouds are intrusting, they are of course, water droplets that gather together to form the white puffy things in the sky. In spring time farmers know that if they see clouds they will not expect any frost to come. Clouds absorb great amounts of heat. This heat is slowly released during the night preventing frost to form.
The heat that comes from the ground (from the sun or inner earth) will radiate out into space unless there were clouds out to reflect and absorb that heat. I believe earth would have been inhabitable if there were no such things as clouds (maybe not all life but all land dwelling things).
When any water vapor that condenses back into liquid water, it will release all energy that would have been necessary for it to become steam. That is a large amount of energy that is put back into the air and sky. This is to say that to convert water into vapor requires a large amount of heat, but when the vapor condenses into water all this heat is given out again.
One last thing, do you know how you would go UP into the mountains and cook, lets say, soup and when you go to eat it, just after boiling it, it seems as if its still cool and not wormed. This is due to the pressure, or lack of it, that is up in the mountains. The less the pressure the cooler the temperature of boil. Just the opposite is something such as a pressure cooker, because of the sealed container the steam builds up causing more and more pressure making the temperature of boil higher and higher; witch will help in cooking food faster. In space if you were to slowly release the pressure in a container with water in it, it would literally ‘boil’ to an ice cube.
This effect is due to the ‘hot’ molecules of water that can escape the surface tension at less and less pressure, until only ‘cold’ water exist, hence it freezes.
So evaporation of water is when all the heat is absorbed (steam), leaving all the slower or colder particles around the area of the water, so in essence it is a cooling process, it absorbed the heat around it to become hotter.
When you freeze water it moves all the heat out, heating everything around it, so in essence it is a heating process. Things around the water become hotter.
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