Question

For problems 1-6, find the average atomic mass of the following mixtures of isotopes. Show your work for full credit. Iodine-127 (80%), Iodine-126 (17%), Iodine-128 (3%)

Answer 1

126.86

Step-by-step explanation:

Iodine-127 (80%)

Iodine-126 (17%)

Iodine-128 (3%)

For a mixture of isotopes, the average atomic mass is obtained by summing the multiplication of the atomic mass and percentage composition of the individual isotopes. This is given as;

Average Atomic Mass = ( 80 / 100 * 127) + (17 / 100 * 126) + (3 / 100 * 128)

Average Atomic Mass = 0.8 * 127 + 0.12 * 126 + 0.03 * 128

Average Atomic Mass = 101.6 + 21.42 + 3.84 = 126.86