Answer:
[tex]\frac{140}{57}La -------->\frac{140}{58} Ce +\frac{0}{-1} \beta[/tex]
Explanation:
Beta emission occurs when a neutron is converted to a proton, an electron and a neutrino. This phenomenon reduces the neutron-proton ratio(N/P).
When a beta emission occurs, the mass number of the daughter nucleus is the same as that of the parent nucleus while the atomic number of the daughter nucleus increases by one unit.
We can see this explanation above in the reaction described in the answer section.
