Avogadro

Definition

Avogadro's number is the number of constituent particles (usually atoms or molecules) contained in one mole of a substance. It is defined as $6.022 \times 10^{23}$ particles per mole.

5 Must Know Facts For Your Next Test

1. Avogadro's number is crucial for converting between atomic scale measurements and macroscopic quantities.
2. The value of Avogadro's number is approximately $6.022 \times 10^{23}$ particles per mole.
3. It allows chemists and physicists to count the number of atoms, ions, or molecules in a given sample by weighing it.
4. Avogadro's number provides the link between the macroscopic scale (grams) and the microscopic scale (atomic mass units).
5. In the kinetic theory of gases, Avogadro's law states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules.

Review Questions

• What is Avogadro's number and why is it important in physics?
• How does Avogadro's number relate to moles and molecular quantities?
• Explain how Avogadro's law applies to gases under identical conditions.

Related terms

Mole: A unit that measures the amount of substance, equivalent to $6.022 \times 10^{23}$ entities (atoms, molecules, etc.).

Ideal Gas Law: $PV = nRT$, which relates pressure ($P$), volume ($V$), amount of gas ($n$), gas constant ($R$), and temperature ($T$).

Boltzmann Constant: $k_B = 1.38 \times 10^{-23} \, J/K$, relates the average kinetic energy of particles in a gas with temperature.