The natural abundance of the three stable isotopes of magnesium are 78.99% magnesium-

24 (23.98504 amu), 10% magnesium-25 (24.9858 amu), and 11.01% magnesium-26

(25.9829 amu). Calculate the atomic weight or atomic mass of magnesium and compare

your value with that given in the Periodic Table. (Note: The units of atomic weight are

atomic mass units (amu).