hobfnst13
Is there a difference in physical state between H2O existing as water vapor and H2O existing in a cloud?
barakn
Yes, the water vapor in the cloud has condensed into micro-droplets. They're not really vapor at that point (although there is still undoubtedly some vapor remaining in the cloud).
Empress Palpatine
...and how would you describe humidity?
Zarkov
Hiya

air usually has water dissolved in it...= water vapour, or a water vapour-pressure

Now we could weigh that water ( condense a volume of air and weigh the liquid water or ice.

[I weigh the absolute water content of air, I use a fixed volume container.. 3 L which I expose to the air... closed the lid and I place the lot in a deep freeze... where the water vapour freezes out onto a metal place as ice crystals... I weigh the metal plate ... then calculate the ABSOLUTE humidity]

the amount of water vapour dissolved in the air is referred to as humidity...

hot air can hold more water than cold air.

QUOTE
Wiki:- The term humidity is usually taken in daily language to refer to relative humidity.

Relative humidity is defined as the amount of water vapor in a sample of air compared to the maximum amount of water vapor the air can hold at any specific temperature in a form of 1 to 100%.

so if we take a volume of cold air with water vapour and heat it (prevent extra water evaporation into that volume of air), the relative humidity goes down... you tell me why ! but the amount of water in that air has not changed.

So a confusing term for many.

In weather reports daily temperature fluctuations cause the local air-mass to gain or lose relative humidity.

The air acts as a pipe for water.... evaporated water here can be transported there a long way off.

The poles is the usual end poin.

Now at the poles the absolute humidity is very very low... very very dry air because it is very cold air.

hope this sparks your interest in Ice Clouds.
iseason
Would an oxygen atom sink or float.? (presuming it could remain seperate)

Just a fun question

Cheers
Iseason
Zarkov
molecular weight O2 = 32

molecular weight H2O = 18

water is so light it is constantly being lost to space.

Lucky for Earth the upper atmosphere is very cold < minus 100 C

so the water vapour turns to ice..... which is less likely to escape into space......

This water becomes a part of the Ice Clouds.
Sapo
Well, good! I made your little list, hm? I needed a laugh, thanks.

Loser.
Enthalpy
O2 won't float nor sink in air or N2 because Brownian movements mix them. Just compare the mass difference of 4 grams (times g and height) to the thermal energy (R*T). Larger-scale atmospheric movements mix them also, more quickly.

More directly: the thickness of the atmosphere (just define properly where it stops...) is the height molecules achieve through their thermal speed, so the whole atmosphe's thickness isn't enough to make a clear difference between 28 and 32 grams.
Moomin
QUOTE (Enthalpy+Mar 28 2008, 02:45 AM)
O2 won't float nor sink in air or N2 because Brownian movements mix them. Just compare the mass difference of 4 grams (times g and height) to the thermal energy (R*T). Larger-scale atmospheric movements mix them also, more quickly.

More directly: the thickness of the atmosphere (just define properly where it stops...) is the height molecules achieve through their thermal speed, so the whole atmosphe's thickness isn't enough to make a clear difference between 28 and 32 grams.

Moreover, that's why argon (A.W 39.95) with atmospheric abundancy of around 0.94% does not stratify - otherwise we'd be in big trouble.

Moomin
Using Zarkov's logic, his brain should've floated off into space years ago - hey, that explains everything!
barakn
QUOTE (Zarkov+Mar 28 2008, 01:28 AM)
water is so light it is constantly being lost to space.

Lucky for Earth the upper atmosphere is very cold < minus 100 C

so the water vapour turns to ice..... which is less likely to escape into space......

This water becomes a part of the Ice Clouds.

You are - as usual - not only completely confused but desperately trying to spread your confusion to others. The outermost layers of the atmosphere are known as the thermosphere and the exosphere (some sources say the exosphere is the outermost part of the thermosphere). Temperatures vary wildly here but often reach over 1000°C, not the "minus 100 C" that you claim.

I bet you were simply extrapolating the cooling trend in the lower atmosphere. It's far more complicated than that. It's warm at the surface, cools off as you go up, but then rises again, then falls again, then rises. Water is not likely to make it past the first cold trap, but if it does it's not going to make it past the second cold trap. Water is not being lost to space, but hydrogen stripped from water is.

iseason
QUOTE (barakn+Mar 28 2008, 06:03 PM)
You are - as usual - not only completely confused but desperately trying to spread your confusion to others.  The outermost layers of the atmosphere are known as the thermosphere and the exosphere (some sources say the exosphere is the outermost part of the thermosphere).  Temperatures vary wildly here but often reach over 1000°C, not the "minus 100 C" that you claim.

I bet you were simply extrapolating the cooling trend in the lower atmosphere.  It's far more complicated than that.  It's warm at the surface, cools off as you go up, but then rises again, then falls again, then rises.  Water is not likely to make it past the first cold trap, but if it does it's not going to make it past the second cold trap.  Water is not being lost to space, but hydrogen stripped from water is.

That is what I thought.

How much impact could the affect have on weather. If water can be stripped into it's parts, then uneven motions based around how the stripping occurs are possible . Aren't they.?

For instance boiling a jug is blamed on moving molecules faster, but oxygen also creates bubbles which create motion in the water....I'm just thinking a scale up ......don't get me wrong. This is still just a fun question......

Cheers
Iseason
Zarkov
QUOTE
Temperatures vary wildly here but often reach over 1000°C,

ionised particles at a very low pressure at "1000C" is not quite like a hunk of steel at 1000C

Once again the method used to measure "temperature" is totally inappropriate.

By the time the water reaches that far is has been split and then ionised

water is continually lost to space... LOL, but it is not H2O as you know it Jim....it is H2 and OH.

PS, it seems quite the thing in net forums to extend what people say in general and claim that the reference in question was specific... so crap flows.

I will not play guys

If you wish to specify extensions for people's interest, go for it.... but don't say I said this and therefore meant that !!!!!!

I address the "average" reader... I am not trying to teach professors... though I don't mind mixing it.

If you took the time to read the OP, then you would realise that the answers given should at least be of interest to the inquirer, but also on-topic and understandable at that level.
hobfnst13
I AM A LITTLE ON THE SLOW SIDE BUT WHAT WOULD BE A SIMPLE WAY TO EXAPLIN THE NSWER..i REALLY APPRECIATE ALL THE INPUT SO FAR
Zarkov
hob

Clouds are like steam that you can see and water vapour is like air ( a gas) that you can not see. Both are just water in different states

now read more if it is still unclear

You have seen sugar or salt crystals dissolving in water until you can't see the crystals any more

well if you boil off the water you will see the crystals again... right? so in one state the crystals can be seen, and in another they can not be seen

now water dissolves in the air as water vapour gas.... so you can't see the water anymore.... we call that evaporation...

You have seen steam.... as white "smoke" that lasts a little while and then disappears

Where does it go ?..... you then seen droplets of water on materials where the steam was.... that steam=water that goes into the air as a gas (vapour) then forms liquid water droplets again.

Steam IS NOT water vapour, you can not see water vapour, it is a gas.

So what is going on !!!!

well if you boil water by heat.... some water molecules escape the liquid and ascend into the air,,,called a vapour or gas

this invisible vapour forms back into tiny water droplets in the cool air=steam... you can see the tiny drops of liquid if you look

Now clouds are like steam that you can see and water vapour is like air ( a gas) that you can not see.

both are H2O, just in different states

Some clouds that are much higher than condensation clouds (droplets of liquid water) are not made of liquid water drops, instead they are made of ice crystals... Ice is water in another state, the solid sate

You need to do some experiments, like boil a kettle... see the "steam" comes out invisible then turns into white smoke...

place a cold plate in the visible steam and see it turn back into liquid water again.

if not maybe wear kitchen gloves and BE CAREFUL.

Simple sub-STATES
solid /// liquid ///////// gas...................., then comes plasma
ice......liquid water... water vapour

(everything is a plasma really... but earthlings can't cope with that, so lets leave that)
QUOTE (hobfnst13+Mar 27 2008, 02:20 PM)
Is there a difference in physical state between H2O existing as water vapor and H2O existing in a cloud?

Yes there is a difference.

Water VAPOR is the GASEOUS state of H20.

In this state it is transparent and colorless.

Thus, though there is water vapor in the air around you, you can not see it.

Clouds on the other hand represent this same water vapor that has CONDENSED out of the gaseous state, back to the liquid or solid state.

But they are in VERY TINY droplets, and because the droplets are so small they tend to remain suspended in the atmosphere for some time until they coalesce into larger drops and return to the earth as rain (of if frozen, as snow).

Arthur

barakn
QUOTE (Zarkov+Mar 28 2008, 08:13 AM)
ionised particles at a very low pressure at "1000C" is not quite like a hunk of steel at 1000C

Once again the method used to measure "temperature" is totally inappropriate.

No. According to wiki: "On the microscopic scale, temperature is defined as the average energy of microscopic motions of a single particle in the system per degree of freedom." This applies just as easily to a plasma as it does to a hunk of steel.

You just didn't like the fact that I caught you inventing erroneous "facts" about the upper atmosphere including a bogus temperature. You responded by claiming temperature is inappropriate. If it was as inappropriate as you claim, you wouldn't have mentioned a temperature in the first place.
Zarkov
QUOTE
You responded by claiming temperature is inappropriate

you shouldn't be so sensitive
I was referring to heat capacity and the ability to supply that heat

for earthlings temperature can not be measured in degrees.

DuzmA
Zarkov - allow me to bestow upon you some friendly advice: use the term humanity instead of earthlings. Earthlings might fit with the image that you think you want to have in these forums, but it sounds hackish and keeps a great deal of what you say from being taken seriously. Its very Riley Martinish and that is never a good thing in serious mediums.
Zarkov
QUOTE
keeps a great deal of what you say from being taken seriously

I have been saying all along

DON'T BELIEVE all that you read.... be skeptical, find alternatives...cracks..evidence...

LOL, I don't want people to believe all I say

It is up to you.
Moomin
QUOTE (Zarkov+Apr 4 2008, 08:41 PM)
I don't want people to believe all I say

You've magnificently excelled yourself in this one particular area - nobody believes anything you "say".