Average Atomic Mass Calculator
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How it works
The average atomic mass of an element is calculated from the masses of its isotopes and their relative abundances.
The formula for calculating average atomic mass is:
Average Atomic Mass = Σ (Isotope Mass × Fractional Abundance)
Where fractional abundance is the percentage abundance divided by 100.
For example, if an element has two isotopes:
- Isotope 1: Mass = 10 u, Abundance = 20%
- Isotope 2: Mass = 11 u, Abundance = 80%
The average atomic mass would be: (10 × 0.20) + (11 × 0.80) = 2 + 8.8 = 10.8 u