How many atoms are in one mole?

6.022 × 10^23 atoms, which is Avogadro's number.

Does this work for molecules too?

For molecules, this gives the number of molecules. To get total atoms, multiply by atoms per molecule.

Why is Avogadro's number so large?

Because atoms are incredibly small. It takes about 6 × 10^23 of them to make a countable, weighable amount.

Free Atom Count Calculator

Calculate the number of atoms in a given mass of a pure element.

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Mass of Element

Atomic Mass

g/mol

Number of Atoms

601,648,488,885,188,650,000,000.000

Moles0.9991 mol

Number of Atoms vs Mass of Element

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How to Count Atoms

Formula

N = (mass / atomic mass) × 6.022 × 10^23

Convert grams to moles, then moles to atoms using Avogadro's number.

Example Calculation

How many atoms in 12 g of carbon-12?

01Moles = 12 / 12.011 = 0.999 mol
02Atoms = 0.999 × 6.022 × 10^23
03Atoms ~ 6.02 × 10^23

Frequently Asked Questions

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Understanding Molarity

Learn what molarity is, how to calculate it, and why it matters in chemistry. Covers moles, liters, dilution, and step-by-step examples for preparing solutions.

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Avogadro's Number Calculator

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Molecule Count Calculator

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Grams to Moles Calculator

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