- #1
brake4country
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Homework Statement
The difference between the mass of one oxygen atom and the sum of the masses of its parts is approx. 2.27 x 10^-28 kg. What is the binding energy that holds an oxygen atom together? (The charge on one electron is 1.6x10^-19 C).
Homework Equations
E = mc^2
The Attempt at a Solution
I started off with listing my knowns:
mass = 2.27 x 10^-28 kg
E = what we're solving for
c = 3 x 10^8 m/s
E = (2.27 x 10^-28)(3.8 x 10^8)^2
18.54 x 10^-14 = 1.85 x 10^-15 J
To convert Joules to eV, I divide by the charge on one electron:
(1.85 x 10^-15)/(1.6 x 10^-19) = 1.2 x 10^4 eV.
My book says it's 1.2 x 10^8 eV but I don't know why.