Naked Science Forum

General Science => General Science => Topic started by: paul.fr on 09/03/2007 01:19:38

Title: Why is water wet?
Post by: paul.fr on 09/03/2007 01:19:38

Why is water wet?

Title: Why is water wet?
Post by: another_someone on 09/03/2007 05:59:21

Why is wet that which water is?

To what extent is this a linguistic question, and what extent is it a physical question?

How would you describe wetness.

Water is ofcourse a liquid, and that alone gives it the property of a liquid; water also has peculiar properties of its own, but which of these properties would you regard as wetness?

Title: Why is water wet?
Post by: daveshorts on 09/03/2007 10:00:49

There is a scientific process known as wetting, which is where water will stick to a surface even if you then try and drain away the water. Cotton for example wets very well, where as PTFE doesn't at all and the water just sits on the surface in globules. This is mostly to do with how strongly the water molecules will make hydrogen bonds with the suface.

If they can bond well then they will stick and wet the surface if not like in PTFE then they won't and the water's surface tension will pull it into a globule.

Title: Why is water wet?
Post by: paul.fr on 10/03/2007 13:55:40

Ok. this was a silly question, but...

The reason i asked it here is beacuse this is a family site, when i worked with children this was often a question they would ask.

Also, it sounds such a silly question that some people may have thaught they would look stupid asking such a question. but it is a question children ask. i already look stupid so had no problem asking!

Title: Why is water wet?
Post by: chris on 11/03/2007 15:08:26

I think it's a good question Paul. About 2 years ago we actually had a similar discussion regarding why you emerge "drier" from a cold shower than a warm one. The answer we came up with relates mostly to water viscosity but also the removal of the skin's greasy "sebum" secretions. Water off a duck's back you might say...

http://www.thenakedscientists.com/forum/index.php?topic=1939.0

Chris

Title: Why is water wet?
Post by: paul.fr on 11/03/2007 17:53:32

Quote from: chris on 11/03/2007 15:08:26

I think it's a good question Paul. About 2 years ago we actually had a similar discussion regarding why you emerge "drier" from a cold shower than a warm one. The answer we came up with relates mostly to water viscosity but also the removal of the skin's greasy "sebum" secretions. Water off a duck's back you might say...

http://www.thenakedscientists.com/forum/index.php?topic=1939.0

Chris

Thanks for the link Chris