Message-Id: <3.0.1.16.19970910232606.3acf1d80@157.22.190.2>
Date: Wed, 10 Sep 1997 23:26:06
To: pinhole@exploratorium.edu
From: Dan Gray <dgray@justin-siena.napanet.net>
Subject: Re: wet ice
In-Reply-To: <l03020904b03cec72fe6a@[206.170.177.80]>
>>Help! A student asked me a question in Chem today and my brain froze....he
>>wanted to know why wet things (i.e. tongue, fingers, etc) stick to ice
>>cubes. Is it hydrogen bonding, the liquid on the object (tongue, etc)
>>freezing, combination of both?
>>
>>Thanks for any input you can give!
>>
>>
>>Kathy Saito
>
>Kathy Saito
>
I think its simply freezing. I painfully recall getting my tongue stuck in
the ice cream freezer at the grocery store as a child.
As the warm water on your tomge comes in contact with the cold ice cube,
the ice cube will warm as the molecules between the two collide. However,
the water molecules on your tongue will cool as they lose energy in these
collisions. It's like a cold person shaking hands with a warm one. As one
warms, the other cools - as energy is transferred. Since the amount of
water on a tongue or wet fingers is fairly small, the energy transfer
doesn't need to be very large for the water to freeze.
I think this must be it since my fingers will stick to cold ice if they're
slightly damp, but won't if they're completely dry.
Dan Gray
dgray@justin-siena.napanet.net