Answer:
The correct answer would be : formed nucleus is that of Mn.
Step-by-step explanation:
Alpha decay is a process that is exhibited by unstable molecules to be more stable. During the alpha decay nucleus of the unstable element removes its two protons and two neutrons in a bundle that researchers call an alpha molecule.
Since a particle loses two protons during alpha decay, it changes starting with one component then onto the next.
Co has 27 protons and neutron in its nucleus emits a alpha molecules that contain 2 protons and 2 neutrons
27=2+z
z =25 in periodic table 25 atomic number of Mn.
Thus, the correct answer would be : formed nucleus is that of Mn.