Answer: 64.8
Explanation:Please see attachment for explanation
Ok...what was the question
Beta decay which is also sometimes referred to as beta emission is a phenomenon in which a certain element releases an electron. For this case, each carbon has an atomic number of 6, leaving us with 8 neutrons, now, the mass number will be retained and the atomic number will be decreased by one. Thus, the answer is Boron-14.
The Elements (The Periodic Table.)