Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!aramis.rutgers.edu!alphard.cs.utk.edu!battle
From: battle@alphard.cs.utk.EDU (David Battle)
Newsgroups: sci.nanotech
Subject: Number of atoms in the human body
Summary: Estimate of number of atoms in an "average" human body wanted.
Keywords: atoms
Message-ID: <8905062246.AA19408@athos.rutgers.edu>
Date: 4 May 89 15:23:19 GMT
Sender: nanotech@aramis.rutgers.edu
Organization: Oak Ridge National Labs, Environmental Sciences Division
Lines: 21
Approved: nanotech@aramis.rutgers.edu


I need a good estimate of the number of atoms in the human body.
Back of the envelope calculations give about 10^27 assuming an average
molecular weight of 12 (as in Carbon 12).  The large numbers
of lighter hydrogen atoms may make this number higher, however.
Where would I find a more accurate estimate?  A breakdown by
element (or even isotope) would be nice.

Just for reference, I am a computer scientist, not a biologist,
chemist, etc.

Disclaimer: I try not to have opinions.

					-David L. Battle
					 battle@utkcs2.cs.utk.edu
					 battle@esddlb.esd.ornl.gov

[Back-of-the-envelope calculations also give 10^27 assuming the body
 is mostly water.  Noting that recorded human weights range over
 two orders of magnitude, it's probably a good guess.
 --JoSH]