The mass of the particles on the left hand side is 8.0263 [[atomic mass units|amu]]s, the mass on the right hand side ''only'' 8.0077 amu.<ref>Gerard Piel ''The age of science: what scientists learned in the 20th century'', Basic Books, 2001, p. 144-145</ref> The difference between this masses is .00186 amu, which results in the following back-of-an-envelope calculation:
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The mass of the particles on the left hand side is 8.0263 [[atomic mass units|amu]], the mass on the right hand side ''only'' 8.0077 amu.<ref>Gerard Piel ''The age of science: what scientists learned in the 20th century'', Basic Books, 2001, p. 144-145</ref> The difference between this masses is .00186 amu, which results in the following back-of-an-envelope calculation: