[sci.nanotech] Number of atoms in the human body

battle@alphard.cs.utk.EDU (David Battle) (05/04/89)

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]