Answer: The mass number of the beta particle is 0.
Explanation: There are three types of radioactive decays. One of which is beta minus decay.
In beta minus decay, a neutron gets converted to a proton and electron. The electron released is the beta particle which does not carry any mass.
General reaction for beta- minus decay is given by:
[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+_{-1}^0\beta[/tex]
Where A represents the mass number
Z represents the atomic number
