1. What is Atomic Mass Unit (AMU)?

The atomic mass unit (AMU) is a standard unit of mass that quantifies mass on an atomic or molecular scale. One AMU is defined as one twelfth of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Each element's mass is multiplied by its count in the molecule
• The sum of all atomic masses gives the molecular mass

Example: For H2O (water):

• Hydrogen (H): 1.008 amu × 2 = 2.016 amu
• Oxygen (O): 15.999 amu × 1 = 15.999 amu
• Total AMU = 2.016 + 15.999 = 18.015 amu

3. Importance of AMU Calculation

Details: Calculating molecular mass is essential for stoichiometric calculations in chemistry, determining molar masses, and understanding chemical reactions at the molecular level.

4. Using the Calculator

Tips: Enter the molecular formula using standard chemical notation (e.g., H2O for water, C6H12O6 for glucose). The calculator recognizes common elements and their atomic masses.

5. Frequently Asked Questions (FAQ)

Q1: What elements does this calculator support?
A: It supports common elements including H, C, N, O, Na, Cl, S, P. More elements can be added to the atomic mass database.

Q2: How accurate are the calculations?
A: Calculations use standard atomic weights rounded to 3 decimal places. For precise work, use more exact isotopic masses.

Q3: Can I enter complex formulas with parentheses?
A: This version handles simple formulas. For complex formulas with parentheses, a more advanced parser would be needed.

Q4: What's the difference between AMU and molar mass?
A: AMU is the mass of one molecule, while molar mass is the mass of one mole (6.022×10²³ molecules) of a substance. Numerically, they're equal but have different units.

Q5: Why are atomic masses not whole numbers?
A: Atomic masses account for natural isotopic abundance. For example, chlorine's mass (35.453) reflects the mix of Cl-35 and Cl-37 isotopes.