Avogadro's Number Calculator

Avogadro's Number Calculator

What is a Mole & Avogadro's Number?

In chemistry, atoms and molecules are too small to count individually. To solve this, scientists use a unit called the mole (mol), which is the SI unit for the amount of a substance.

Avogadro's Number (Nₐ) is the constant that defines the mole. It is the exact number of particles (atoms, molecules, ions, etc.) in one mole of a substance.

Nₐ ≈ 6.022 × 10²³ particles/mol

Think of it as a "chemist's dozen." Just as "a dozen" always means 12 of something, "a mole" always means 6.022 × 10²³ of something. This number is the essential bridge that connects the microscopic world of atoms (which we can't see) to the macroscopic world of grams (which we can measure on a scale).

Frequently Asked Questions

Who was Avogadro?

Amedeo Avogadro was an Italian scientist in the early 19th century. He proposed a hypothesis (now a law) stating that equal volumes of gases at the same temperature and pressure contain an equal number of particles. While he didn't discover the constant itself, his work laid the foundation for it, and the number was named in his honor.

Why is Avogadro's number so large?

Because atoms are incredibly, unimaginably small. It takes this many atoms (602,214,076,000,000,000,000,000) just to have enough of a substance to work with on a human scale. For example, 1 mole of carbon atoms (6.022 × 10²³ atoms) has a mass of just 12 grams.

Does this work for atoms, molecules, ions, or electrons?

Yes. The mole is a unit for an *amount* of anything. You can have a mole of atoms (e.g., in a block of iron), a mole of molecules (e.g., in a glass of water, H₂O), a mole of ions (e.g., Na⁺ in salt water), or even a mole of electrons in an electrical calculation. The number is always 6.022 × 10²³.