Question
Mon November 28, 2011 By:

Why do the 1/12 mass of of carbon atom is taken as 1u

Expert Reply
Mon November 28, 2011
A carbon atom has 6 protons and 6 neutrons.
This equals 12.000u & 1u is one-twelfth the mass of an atom of carbon.
1u =1.661x10^-24g
so 6 protons plus 6 neutrons should equal the carbon-12 atom in grams
and this divided by 12 should equal 1u =1.661x10^-24g
proton weight in grams (1.672622 x 10^-24g)
neutron wight in grams (1.674927 x 10^-24g)
1.672622 x 6
+ 1.674927 x 6
-------------------
20.085294g
divide this by 12 = 1.67 x 10^-24g
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