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# Beta + decay mass conservation question Watch

1. In the equation representing beta + decay where a proton decays into a neutron:

proton -> neutron + positron + neutrino

How is mass being conserved in this equation? From my understanding, isn't the mass of a proton slightly less than the mass of a neutron? Even more, a positron also has mass and so does a neutrino (albeit very very small). Overall the equation doesn't look balanced to me because the right side seems to hold more mass.
2. (Original post by scientific222)
In the equation representing beta + decay where a proton decays into a neutron:

proton -> neutron + positron + neutrino

How is mass being conserved in this equation? From my understanding, isn't the mass of a proton slightly less than the mass of a neutron? Even more, a positron also has mass and so does a neutrino (albeit very very small). Overall the equation doesn't look balanced to me because the right side seems to hold more mass.
Energy and mass equivalence E=mc2

The binding energy of the proton is converted to mass in the decay. The energy of the constituent parts reduces as a result.
3. (Original post by uberteknik)
Energy and mass equivalence E=mc2

The binding energy of the proton is converted to mass in the decay. The energy of the constituent parts reduces as a result.
Thanks a lot. I was also wondering if you could answer another question on the topic if you don't mind. Here is a picture of an equation (beta minus decay) in my textbook.

From what I know when they represent the nucleus of elements using the superscripts and subscripts; the top number is the nucleon number (proton + neutron), and the bottom number is the proton number. So why is it that for an electron they are representing a negative charge in the space where the proton number usually is? Shouldn't that space be zero for an electron?

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