Answer :
Barium-149 undergoes beta decay to produce an unknown daughter nuclide and a beta particle. During beta decay, a neutron in the nucleus is transformed into a proton, releasing a beta particle (an electron) and an antineutrino.
1. In this case, after the decay of Barium-149, one of the neutrons in the nucleus is transformed into a proton, resulting in the formation of the daughter nuclide.
2. The daughter nuclide produced in this process is called Lanthanum-149. This is because a neutron in Barium-149 changes into a proton, increasing the atomic number by 1, leading to the formation of Lanthanum-149.
Therefore, the daughter nuclide produced when Barium-149 undergoes beta decay is Lanthanum-149.
