You can see the table here: https://people.physics.anu.edu.au/~ecs103/chart/?ShowStable=true&ShowYork=false&EvenEven=false&ColourRange=300&ColourSaturation=1&Co

You can see the table here: https://people.physics.anu.edu.au/~ecs103/chart/?ShowStable=true&ShowYork=false&EvenEven=false&ColourRange=300&ColourSaturation=1&ColourLightness=0.7&ColourOffset=0&BackgroundLightness=1&BackgroundTransparent=false&FontBold=false&FontItalic=false&FontSmallCaps=false&FontSize=1&FontName=Roboto&ShowElementLabels=true&InitialPropertyCode=dm&CurrentDataMode=x&zoomLevel=34&nleft=113.27893504027098&ztop=91.19310887403375& https://people.physics.anu.edu.au/~ecs103/chart/?ShowStable=... When I click on the lead-208 box, it credits data from: NUBASE2020: https://doi.org/10.1088/1674-1137/abddae https://doi.org/10.1088/1674-1137/abddae AME2020: https://doi.org/10.1088/1674-1137/abddb0 https://doi.org/10.1088/1674-1137/abddb0 It also only says that alpha decay is “possible”, not that it happens with any frequency—in fact, it lists Pb-208 as stable.