# Mass/charge balance of Beta decay/nuclear reactions

## Homework Statement

There are three different reactions we did in class.
B-: 6C14 --> 7N14 + e-
B+: 6C11 --> 5B11 + e+
Nuclear rxn: alpha particle + 7N14 --> 8O17 + e+

## Homework Equations

Q tot = (mass inital - mass final) * 931.5 MeV
Charge balance

## The Attempt at a Solution

In class, for B- the teacher wrote down:
Q= (Mass of C nucleus) - (mass of N nucleus) - 1 e-
= (mass of C atom - 6 e-) - (mass of N atom - 7 e-) - (mass of 1 e-)
so -6 -(-7) - 1 = 0 so Q= (mass of C atom) - (mass of N atom)

B+
Q = (mass of C nuc) - (Mass of B nuc) - (mass of e+)
Q= (mass of C atom - 6 e-) - (mass of B atom - 5 e-) - mass of 1 e-
Q= -6 -(-5) -1 = -2, so he said Q total = (mass of C) - (mass of B + 2e-)

Nuclear rxn
Q = (mass of alpha nuc) + (mass of N nuc) - (mass of O nuc) - (mass of e+)
Q = (mass of He - 2 e-) + (mass of N atom - 7 e-) - (mass of O atom - 8 e-) - (mass of e+)
Q = -2 + -7 - (-8) -1 = -2 e-
However, he said in class that the Q = (mass of alpha particle + mass of N atom) - (mass of O atom)
Can someone please clear this up for me? I really don't get the charge/mass balance. Thanks so much