Path: utzoo!mnetor!uunet!husc6!purdue!umd5!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: sci.misc
Subject: Re: ice cubes
Message-ID: <11015@mimsy.UUCP>
Date: 11 Apr 88 12:08:37 GMT
References: <7549@iuvax.cs.indiana.edu>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 24
Keywords: float

In article <7549@iuvax.cs.indiana.edu> seeker@iuvax.cs.indiana.edu (Karen
Lynn White) writes:
>Can somebody tell me exactly why ice cubes float?

Easy: they are less dense than water.

Okay, why are they less dense than water?

The answer lies in something called `hydrogen bonding'.  There is
a weak attraction between the hydrogen atoms in one water molecule
and the oxygen atom in another.  This force is too weak to have
much effect on water, especially above 3 or 4 degrees C, but below
that temperature, and most of all in ice, it tends to arrange the
molecules into tetrahedral patterns.  These take more space than
the random arrangements, which makes the ice less dense than the
water.

Molecular biologists can tell you more about how hydrogen bonding
is important to life-as-we-know-it.  Apparently it is part of
the reason DNA works.  `Gosh Mr. Science, you mean we're alive
because ice floats?' `That's right kids!  Isn't science amazing?' :-)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris