Question

Three magnesium isotopes have atomic masses and relative abundance of 23.985 amu (78.999%), 24.986 amu (10.000%), and 25.982 amu (11.01%). Calculate the average atomic mass of magnesium.

Answer 1

The average atomic mass of magnesium is calculated by multiplying each isotope's atomic mass by its relative abundance and summing the results, which gives approximately 24.31 amu.

Step-by-step explanation:

To calculate the average atomic mass of magnesium, we'll use the atomic masses and relative abundances of its isotopes. The formula for average atomic mass is:

M_{avg} = (Mass_{isotope1} \times Abundance_{isotope1}) + (Mass_{isotope2} \times Abundance_{isotope2}) + ... + (Mass_{isotopeN} \times Abundance_{isotopeN})

Substituting the given values into the formula, we get:

M_{avg} = (23.985 amu \times 0.78999) + (24.986 amu \times 0.10000) + (25.982 amu \times 0.1101)

M_{avg} = (18.9501515 amu) + (2.4986 amu) + (2.859962 amu)

M_{avg} = 24.3087135 amu

So, the average atomic mass of magnesium is approximately 24.31 amu.