Radon-220 will eventually decay to Bismuth-212 as 

${ }_{86}{\mathrm{Rn}}^{220}{\to }_{84}{\mathrm{Po}}^{216}{+}_2{\mathrm{He}}^4$; half life =55s, 

${ }_{84}{\mathrm{Po}}^{216}{\to }_{82}{\mathrm{Pb}}^{212}{+}_2{\mathrm{He}}^4$; half life =0.016s; 

${ }_{82}{\mathrm{Pb}}^{212}{\to }_{83}{\mathrm{Bi}}^{212}{+}_{-1}{\mathrm{e}}^0$; half life =10.6h.

If a certain mass of Radon-220 is allowed to decay in a certain container ,after 10 minutes the elements with the greatest mass will be