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Average Atomic Mass Formula:
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The average relative atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of an element. It accounts for both the mass and relative abundance of each isotope.
The calculator uses the formula:
Where:
Explanation: The calculator sums the product of each isotope's mass and its relative abundance to determine the weighted average atomic mass.
Details: Calculating average atomic mass is fundamental in chemistry for determining the atomic weights of elements as they appear on the periodic table. This value is essential for stoichiometric calculations, chemical analysis, and understanding elemental properties.
Tips: Enter the mass of each isotope in atomic mass units (amu) and its fractional abundance (between 0 and 1). You can add multiple isotopes using the "Add Another Isotope" button. The sum of all abundances should ideally be 1 (100%).
Q1: Why is the average atomic mass not a whole number?
A: The average atomic mass is a weighted average of all naturally occurring isotopes of an element, which typically have different masses and abundances.
Q2: What if the sum of abundances doesn't equal 1?
A: The calculator will still work, but the result represents the average based on the provided abundances. For accurate results, the sum should be 1 (100%).
Q3: How many isotopes can I calculate for?
A: You can add as many isotopes as needed using the "Add Another Isotope" button.
Q4: What units should I use for mass and abundance?
A: Mass should be in atomic mass units (amu), and abundance should be a decimal fraction between 0 and 1.
Q5: Can I use percentage abundances instead of fractions?
A: You would need to convert percentage to fraction by dividing by 100 (e.g., 25% = 0.25).