Path: utzoo!mnetor!uunet!husc6!mailrus!ames!ncar!boulder!cu-den!udenva!agranok
From: agranok@udenva.cair.du.edu (Alex B. Granok)
Newsgroups: sci.misc
Subject: Re: ice cubes
Message-ID: <10167@udenva.cair.du.edu>
Date: 12 Apr 88 17:39:11 GMT
References: <7549@iuvax.cs.indiana.edu>
Reply-To: agranok@udenva.UUCP (Alexander B. Granok)
Organization: U of Denver
Lines: 19
Keywords: float
Summary: Crystal structure of ice.

In article <7549@iuvax.cs.indiana.edu> seeker@iuvax.cs.indiana.edu (Karen Lynn White) writes:
>This is a serious question, no flames please.
>
>Can somebody tell me exactly why ice cubes float?  It seems I ought to know
>but I don't.

It is like this:  

Water is one of nature's most intriguing substances in that it becomes less
dense when it freezes.  The reason for this is the extensive hydrogen bonding
in water.  At low temperatures (like when it freezes), the hydrogen bonds form
a complex, ordered network that holds the water molecules in a tetrahedral (I
think) lattice.  As the ice heats up and the molecules vibrate more, the latticebreaks down and the water basically "collapses" on itself, causing an increase
in density.  Ice floats because it is less dense than liquid water.

-- 
                                           
Alexander B. Granok  			"I love school...              
ncar(hao)!udenva!agranok                         it's the work I hate."