Isotope Mass Calculator Formula

Average Atomic Mass Formula:

\[ \text{Average Atomic Mass} = \sum \left( \frac{\text{Mass}_i \times \text{Abundance}_i}{100} \right) \]

Mass 1 (u):

Abundance 1 (%):

Mass 2 (u):

Abundance 2 (%):

Average Atomic Mass:

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1. What is the Average Atomic Mass Formula?

The average atomic mass formula calculates the weighted average mass of all isotopes of an element based on their natural abundances. It provides a more accurate representation of an element's atomic mass as found in nature.

2. How Does the Calculator Work?

The calculator uses the average atomic mass formula:

\[ \text{Average Atomic Mass} = \sum \left( \frac{\text{Mass}_i \times \text{Abundance}_i}{100} \right) \]

Where:

\( \text{Mass}_i \) — Mass of isotope i (atomic mass units, u)
\( \text{Abundance}_i \) — Natural abundance of isotope i (percentage)
The sum is taken over all isotopes of the element

Explanation: The formula calculates a weighted average where each isotope's contribution is proportional to its natural abundance.

3. Importance of Average Atomic Mass Calculation

Details: Calculating average atomic mass is essential for understanding chemical properties, stoichiometric calculations, and predicting chemical behavior of elements in compounds and reactions.

4. Using the Calculator

Tips: Enter the mass of each isotope in atomic mass units (u) and their corresponding natural abundances as percentages. The sum of all abundances should equal 100% for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: Why is average atomic mass different from mass number?
A: Mass number refers to a specific isotope's total protons and neutrons, while average atomic mass considers all isotopes and their abundances.

Q2: What if an element has more than two isotopes?
A: The formula can be extended to include additional isotopes by adding more (mass × abundance/100) terms to the sum.

Q3: Why are atomic masses on the periodic table not whole numbers?
A: They represent weighted averages of all naturally occurring isotopes, accounting for their different masses and abundances.

Q4: How precise are average atomic mass calculations?
A: Very precise when accurate mass and abundance values are used, typically to 4-6 decimal places in atomic mass units.

Q5: Can this calculator handle elements with more than two isotopes?
A: This version calculates for two isotopes, but the formula can be expanded for elements with more isotopes.