11. Particles often undergo a series of radioactive 238 decays before they reach a stable isotope. This is true of U-238, which undergoes a series of 14 234 a decay alpha and beta decays to reach Lead-206 which 230 B decay is a stable isotope. This can be shown visually in a type of graph known as a decay series. 226 Complete a series of 14 reactions showing the 222 Mass number, A decay of U-238 to Lead-206 showing all relevant 218 particles 214 210 206 82 83 84 85 86 87 88 89 90 91 92 Pb Bi Po At Rn Fr Ra Ac Th Pa U Number of protons, Z