1. What is Atomic Mass?

Atomic mass is the weighted average mass of all naturally occurring isotopes of an element, taking into account their relative abundances. It's expressed in atomic mass units (amu) and appears on the periodic table for each element.

2. How Does the Calculator Work?

The calculator uses the atomic mass formula:

Where:

• Isotope Mass — Mass of each isotope in atomic mass units (amu)
• Abundance — Natural abundance of each isotope as a percentage

Explanation: The calculator sums the product of each isotope's mass and its fractional abundance (percentage divided by 100).

3. Importance of Atomic Mass Calculation

Details: Accurate atomic mass is essential for stoichiometric calculations in chemistry, determining molar masses, and understanding isotopic composition of elements.

4. Using the Calculator

Tips: Enter each isotope's mass in amu and its natural abundance in percentage. You can add multiple isotopes to calculate the weighted average atomic mass. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is atomic mass not a whole number?
A: Atomic mass is a weighted average of all naturally occurring isotopes, which typically have different masses and abundances.

Q2: How precise should my isotope mass values be?
A: For most calculations, 4 decimal places (e.g., 15.9949 amu for oxygen-16) provides sufficient precision.

Q3: What if my abundance percentages don't add up to 100%?
A: The calculator will still work, but results may not reflect real-world elements where abundances always sum to 100%.

Q4: Can I use this for radioactive elements?
A: Yes, but natural abundances may vary depending on the source due to radioactive decay over time.

Q5: How does this relate to molar mass?
A: The atomic mass in amu is numerically equal to the molar mass in g/mol for any given element.