Home Back

Relative Atomic Mass of Element Calculator

Relative Atomic Mass Formula:

\[ Ar = \frac{M_{element}}{\left(\frac{1}{12}\right) \times M_{C-12}} \]

kg
kg

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is Relative Atomic Mass of an Element?

Definition: Relative Atomic Mass of an Element is defined as the ratio of the average mass of atom of specific composition to the 1/12th of the mass of atom of nuclide C-12.

Purpose: It provides a standardized way to compare atomic masses across different elements.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Ar = \frac{M_{element}}{\left(\frac{1}{12}\right) \times M_{C-12}} \]

Where:

Explanation: The mass of the element's atom is compared to 1/12th the mass of a Carbon-12 atom, which serves as the standard reference.

3. Importance of Relative Atomic Mass

Details: This measurement is fundamental in chemistry for stoichiometric calculations, determining molecular formulas, and understanding chemical reactions.

4. Using the Calculator

Tips: Enter the mass of the atom in kilograms and the mass of Carbon-12 atom (default 0.0120116 kg). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is Carbon-12 used as the standard?
A: Carbon-12 was chosen as the standard because it's a stable isotope with a well-defined mass and is easy to work with experimentally.

Q2: What's the typical mass of a Carbon-12 atom?
A: The exact mass is 1.992646547 × 10⁻²⁶ kg, but for practical calculations, 0.0120116 kg per mole is often used.

Q3: How precise should my measurements be?
A: For accurate results, measurements should be as precise as possible, ideally using mass spectrometry data.

Q4: Can I use atomic mass units (u) instead of kilograms?
A: Yes, but the calculator would need to be modified since it currently expects kilogram inputs.

Q5: How does this relate to molar mass?
A: The relative atomic mass in grams becomes the molar mass of the element (grams per mole).

Relative Atomic Mass of Element Calculator© - All Rights Reserved 2025