Lead-208 (82208Pb) is known to be formed directly through a single alpha decay.
a. (i) Identify the parent nuclide that decayed to produce 82208Pb.
b. (ii) Write the balanced nuclear equation for the decay.
c. (iii) State the proton number and neutron number of the parent nuclide.
d. (iv) By what percentage did the proton number change in this decay? Show your working.