Magnesium has three naturally occurring isotopes with masses of 23.99 amuamu, 24.99 amuamu, and 25.98 amuamu and natural abundances of 78.99%%, 10.00%%, and 11.01%%, respectively. Calculate the atomic mass of magnesium.

24.309 g/mol

Explanation:

To get the atomic mass, all we have to do is calculate with the masses of the three isotope, the real quantity present, taking account of the percent and then, do a sum of these three values. Like a pondered media.

For the first isotope:

23.99 * (78.99/100) = 18.95 g/mol

For the second isotope:

24.99 * (10/100) = 2.499 g/mol

For the last isotope:

25.98 * (11.01/100) = 2.86 g/mol

Now, let's sum all three together

AW = 18.95 + 2.499 + 2.86

AW = 24.309 g/mol