[Alison Leverett]

Alison Leverett  asked the Naked Scientists:
   
Hi.

I am not very well educated, and unfortunately for my 10 and 11 year old sons, I'm home-schooling them! (poor kids!)

Can you tell me, is the process of water naturally seeking dry air to saturate similar to the process of heat naturally seeking and "transferring to" or "exchanging with" coolness? 

I read the postings explaining how clothes dry if just hanging in a room at room temperature and that is what I deduced.  Is that correct?

I also have another somewhat related question:

I understand that when salty ocean water evaporates, the salt and other minerals are left behind and the clean water goes into the atmosphere. 

What happens to the other "ingredients" (chemicals or what-not) in other liquids? 

Does the water evaporate cleanly out of any substance containing water (say - pardon the vulgarity of this question) urine from a dog on the street, spit on the street, etc. 

Does the water content evaporate cleanly leaving the undesirable residue, or does some of that residue float in the air as well?

Okay, and, if you don't mind, one more question also related. 

When water evaporates into the air, does it all go up to form clouds or does some just hang around at a lower level and why?  What determines which "clean" water vapour molecules go up and which linger?

Thank you so much for taking the time to help me.
 
Alison

What do you think?

[geo driver]

not an academic ether, i thought mist was a cloud without the will to fly.  is there a difference in pressures and energy.

pressure, in this sense, is the amount or weight of air pushing down on us, it is caused and affected by lots of different things the sun being a major player. Think of a kettle you put it on to boil, and steam comes out when its hot, that is one effect of the pressure, now think of the sun as the heating element of your kettle, the sun warms up a piece of air, the particles in the air get really happy and start to move around, creating high pressure, pushing things away from it.  Low pressure is like the condensation on a mirror once the air gets colder it slows down becomes heaver and falls.  This is what happens in the weather, warm air rises creating high pressure, colder air (the low pressure) hits it and creates wind/rain and many other wonderful tricks the sky can throw at us.

i wrote the last bit ages ago and always ment to get you guys to tell me yea or nay

[geo driver]

ohhh also water is..... magnetic it likes to make friends and keep together forming very briefly hydrogen bonds.  its the same as when your driving your car when its raining or taking a shower, ever seen the beads of water following each other this is because of the stickyness of water i like to stick together.

Also water loves dry places and will try to move there, even up hill draging its mates with it.  you can see this happening, when you put a suger lump half way into a cup of tea and watch the coloured water move up it.

BTW all of the above could be codswalop so i await confirmation from some of the more intelligent people on here.

[geo driver]

iv probably done more damage. but i have found with my niece's that giving human terms happy, slow will effort, helps them gain an interest in the subject making them look stuff up after, and of course when they have looked stuff up they love correcting me on what i told them in the first place, and i love that we learn together . i suppose excited would of been a better term?

[echochartruse]

Where does humity fit in and what exactly is it.