Answer
a) $^{44}_{19}$K --> $^{44}_{20}$Ca + $^0_{-1}$e
b) $^{59}_{26}$Fe --> $^{59}_{27}$Co + $^0_{-1}$e
c) $^{42}_{19}$K --> $^{42}_{20}$Ca + $^0_{-1}$e
d) $^{141}_{56}$Ba --> $^{141}_{57}$La + $^0_{-1}$e
Work Step by Step
In the beta decay of an isotope the resulting product is one beta particle ( $^0_{-1}$e) plus a new isotope of a different element that is one higher on the Periodic Table than the original, but with the same mass number. This is because to balance the equation, one proton +1 must be added to the atomic number of the base isotope to cancel the beta particle.
