Question 1

What is Avogadro's number?

Accepted Answer

Avogadro's number (N_A) is 6.02214076 × 10²³ mol⁻¹. It is the number of constituent particles (atoms, molecules, ions, etc.) in one mole of a substance. This constant connects the macroscopic scale (grams, liters) to the atomic scale.

Question 2

Why is Avogadro's number so large?

Accepted Answer

Atoms and molecules are incredibly small. Avogadro's number is chosen so that one mole of carbon-12 has a mass of exactly 12 grams. Since each carbon atom has a mass of about 2 × 10⁻²³ grams, you need about 6 × 10²³ of them to make 12 grams.

Question 3

What is a mole?

Accepted Answer

A mole is the SI unit for amount of substance. One mole contains exactly 6.02214076 × 10²³ particles. It is the chemist's counting unit, analogous to a dozen (12) but much larger.

Question 4

Can Avogadro's number apply to any particle?

Accepted Answer

Yes. Avogadro's number applies to atoms, molecules, ions, electrons, or any countable entity. One mole of iron atoms, one mole of water molecules, and one mole of sodium ions all contain the same number of particles.

Avogadro's Number Calculator

Frequently Asked Questions