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152 bytes added ,  22:01, December 14, 2009
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Clarified discussion on excess energy in alpha decay
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Note that the particle count is conserved, meaning on the left there are 92 protons, and on the right there are 2 + 90 = 92 protons as well. Likewise, the atomic masses are balanced, since on the left the total is 238, and on the right the total is 4 + 234 = 238.
 
Note that the particle count is conserved, meaning on the left there are 92 protons, and on the right there are 2 + 90 = 92 protons as well. Likewise, the atomic masses are balanced, since on the left the total is 238, and on the right the total is 4 + 234 = 238.
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However, from just this equation, it is difficult to understand how energy is balanced, too. Because this is a naturally occurring decay, we expect that the energy contained within the alpha particle and the Thorium atom will be <b>less than</b> the energy contained within the Uranium atom (because of the law of Entropy). So, where is that extra energy? It is released from the reaction in the form of a weak gamma emission.
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However, from just this equation, it is difficult to understand how energy is balanced, too. Because this is a naturally occurring decay, we expect that the energy contained within the alpha particle and the Thorium atom will be <b>less than</b> the energy contained within the Uranium atom (because of the law of Entropy). So, where is that extra energy? We find the "missing" energy in the kinetic energies of the daughter products. This means that the alpha particle may be ejected from the original atom with significant speed (since kinetic energy is the energy of motion).
    
==Analogy to disease==
 
==Analogy to disease==
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