What would be the daughter product of the beta decay of lead-212 and what would be the daughter product of the alpha decay of polonium-216?

lead with Z = 82 is transformed into Bismuth with Z = 73

The Po with Z = 84 becomes Pb with Z = 82

Explanation:

Beta decay occurs when a neutron emits an electron and an anti neutrino from the atomic nucleus, therefore the atomic number of the material increases by one unit.

           Pb + e + ν → Bi

lead with Z = 82 is transformed into Bismuth with Z = 73

In alpha decay, a helium nucleus is emitted from the nucleus of the atom, therefore the atomic number decreases by two units.

         Po +α → Pb

The Po with Z = 84 becomes Pb with Z = 82