Question

Natural magnesium occurs as a mixture of three isotopes: Mg 24 12 at 78,8%, Mg 25 12 at 10,1% and Mg 26 12 at 11,2%. Calculate the atomic mass of a natural sample of magnesium.

Answer 1

$A=0.788\cdot 24+0.101\cdot 25+0.112\cdot 26=24 .3.$