Avogadro’s number is a fundamental constant in chemistry that represents the number of particles—such as atoms, molecules, or ions—present in one mole of a substance. Its value is 6.022 × 10²³.
This means that if you take one mole of any element or compound, it will contain exactly 6.022 × 10²³ particles of that substance, regardless of what the substance is. For example:
- One mole of oxygen molecules (O₂) contains 6.022 × 10²³ oxygen molecules.
- One mole of sodium atoms contains 6.022 × 10²³ sodium atoms.
Avogadro’s number provides a bridge between the microscopic world of atoms and molecules and the macroscopic world that we can measure in grams and liters. It helps chemists relate mass and volume to the actual number of particles involved in chemical reactions.