0.9902439024390244
the overall atomic mass is 204.37, but for thallium 203 it is 203, and for thallium 205, it is 205.
The number 203 and 205 have no common factors. 203 = 7 x 29 205 = 5 x 41
101.5
205
34.1667
67.6667
Find the average of your readings. Divide 220 volts into it and you will have your answer.
(203 x 0.30) = 60.9 (205 x 0.70) = 143.5 60.9 + 143.5 = 204.4 The answer is 204.4 amu !
205
1.1429
7
203