Answer :
To find the average atomic mass of magnesium, multiply each isotope's mass by its relative abundance, then add the results. The average atomic mass is 24.2907 amu.
The average atomic mass of an element is calculated by multiplying the mass of each of its isotopes by its relative abundance, and then summing these values. For magnesium, this calculation would be as follows:
(0.7870 imes 23.9850 amu) for 24Mg
(0.1003 imes 24.9858 amu) for 25Mg
(0.1117 imes 25.9826 amu) for 26Mg
Now, we calculate each contribution:
18.8855 amu (78.70% of 23.9850 amu)
2.5082 amu (10.03% of 24.9858 amu)
2.8970 amu (11.17% of 25.9826 amu)
Adding these contributions together, we get the average atomic mass of magnesium:
Average atomic mass = 18.8855 amu + 2.5082 amu + 2.8970 amu = 24.2907 amu
Therefore, the average atomic mass of magnesium is 24.2907 amu.
