1. What is Average Atomic Mass?

The average 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.

2. How Does the Calculator Work?

The calculator uses the average atomic mass formula:

Where:

• \( iso \) — Isotope mass (atomic mass units)
• \( abun \) — Natural abundance of the isotope (decimal)

Explanation: The formula calculates the weighted average of all naturally occurring isotopes of an element, where each isotope's contribution is proportional to its natural abundance.

3. Importance of Average Atomic Mass Calculation

Details: Average atomic mass is crucial in chemistry for stoichiometric calculations, determining molecular weights, and understanding the composition of elements as they occur naturally.

4. Using the Calculator

Tips: Enter the mass of each isotope in atomic mass units (u) and its abundance as a decimal (e.g., 0.25 for 25%). The sum of all abundances must equal 1. You can calculate for elements with 2 or 3 naturally occurring isotopes.

5. Frequently Asked Questions (FAQ)

Q1: Why is the average atomic mass not a whole number?
A: It's a weighted average of different isotopes, each with different masses, so it typically results in a decimal value.

Q2: How many isotopes can I calculate for?
A: This calculator supports up to 3 isotopes. For elements with more isotopes, you would need to add additional fields.

Q3: Why must the abundances sum to 1?
A: The abundance values represent the proportion of each isotope in nature, and all proportions together must account for 100% of the element.

Q4: What units are used for atomic mass?
A: Atomic mass is typically measured in atomic mass units (u), where 1 u is defined as 1/12 the mass of a carbon-12 atom.

Q5: Can I use percentage values instead of decimals?
A: No, the calculator requires decimal values (e.g., 0.25 instead of 25%). Convert percentages to decimals by dividing by 100.