EW"VQ"EJV FPI"1: JùC"JE"JV"PJồP I Nguyờn t trung bỡnh ca U = 99, 28x238 - 0, 72x235 ? 237,98 100 10 NA 237,98x3 - 16x8 - Te"8 rjÔp"tô"8i vi U238 : v = k x N = ln2 /t 1/2 x N 10 N A xln2/(4,5.109.365.24.3600)= 1,04x105(Bq) =0,9928x3 237,98x3 - 16x8 10 NA N = 0,0072x3x 237,98x3 - 16x8 - Te"8 rjÔp"tô"8i vi U235 v = k x N = ln2/ t 1/2 x N 10 =0,0072x3 N A xln2/(7,1.108.365.24.3600)= 4,78x103(Bq) 237,98x3 - 16x8 II Ta cú: 90 Th232 82 Pb208 + x He4 + y -1 e0 N = 0,9928x3x 90 = 82 + 2x - y 232 = 208 + 4x Rỳt ra: x= 6, y = Vy s rjÔp"tô"g