Nuclei Are Count Ledgers

Beta Minus Keeps Mass Number

Beta-minus decay changes Z while keeping A fixed. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Beta-minus keeps mass number fixed

The parent and daughter both have A 14, but Z increases from 6 to 7.

14=146+1=714=14\quad 6+1=7
Beta-minus ledgerMass number is unchanged while proton count rises.beta-minusparent A=14 Z=6 N=8daughter A=14 Z=7 N=7emit A=0 Z=-1dE=0 J

One neutron becomes one proton in the nucleus ledger

The neutron count moves from 8 to 7 as the proton count rises.

8−1=78-1=7
Beta-minus neutron countThe beta particle is schematic; the count rule is checked.beta-minusparent A=14 Z=6 N=8daughter A=14 Z=7 N=7emit A=0 Z=-1dE=0 J