křemík -9 -9 -10 -10 -10 -10 Si-31 0,020 1,9.10 0,010 1,0.10 5,1.10 3,0.10 1,8.10 1,6.10 -9 -9 -9 -9 -10 -10 Si-32 0,020 7,3.10 0,010 4,1.10 2,0.10 1,2.10 7,0.10 5,6.10