Atomic mass unit (AMU)
Name: mark h chu
What's the difference between AMU and gram atomic mass?
The atomic mass unit, or amu, is defined so that the mass
of 1 mole of carbon atoms is exactly 12.000000000 amu.
The amu has the added convenience of being equal to units
of grams per mole; 1 amu = 1 gram/mole. So, one mole of
C12 weighs 12.00000000 grams. I believe that this is strictly
true....someone correct me if I am mistaken.
The atomic mass unit (amu) is defined to be exactly
1/12 of the mass of a C-12 atom (Not a mole of carbon
atoms...) Therefore 1 C-12 atom has a mass of exactly
12.00000000 amu. Also, therefore, 1 amu is a very
small unit of mass - specifically 1amu = 1.66053X10^-24 grams.
1.00 mole of C-12 atoms has a mass of 12.0000000 grams!
P.S. Most college level general text books do not
refer specifically to gram atomic weight. I got the
above information from Brown, LeMay and Bursten - "Chemistry-
The Central Science" (That Brown is not me.)
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Update: June 2012