The answer is c, Polonium. An alpha particle contains two protons hence the original atom must have an atomic number 2 greater than Pb (lead). Looking at the periodic table we can see that that element is Po. Solution The answer is c, Polonium. An alpha particle contains two protons hence the original atom must have an atomic number 2 greater than Pb (lead). Looking at the periodic table we can see that that element is Po..