Beginner Topic 26 of 1102 Atomic Structure & Periodicity
Mole
The amount of substance containing exactly 6.022 x 10^23 elementary entities.
Practise Atomic Structure & Periodicity All Atomic Structure & Periodicity topics
In-depth explanation of Mole
The mole is the SI base unit of amount of substance and counts entities using the fixed number 6.02214076 x 10^23. It connects the microscopic world of atoms and molecules with the macroscopic quantities of grams and litres that can be weighed or measured. One mole of any substance contains the same number of particles, whatever their individual masses. The molar mass in grams per mole numerically equals the relative formula mass, so a mole of water weighs 18.02 g. One mole of an ideal gas occupies about 22.4 litres at 0 degrees C and 1 atm.
Going deeper: Mole
Key ideas: One mole contains exactly 6.02214076 x 10^23 entities, the amount of substance in SI (mol). Core conversions: n = m / M, n = N / N_A, and for gases at STP n = V / 22.4 L (at 0 C and 1 bar, 22.7 L). Always state what entities you count, such as moles of atoms versus moles of molecules.
Common mistakes and connections: Students forget that 1 mol of O2 has 2 mol of O atoms, or mix up moles with mass. A mole is a count like a dozen, not a mass or a weight. It is the central link between the microscopic and macroscopic scale, used in stoichiometry, concentration and gas laws.
Visualization of Mole
One mole of any ideal gas occupies about 22.4 L at 273 K and 1 atm, a familiar link between a counted amount of particles and a measurable volume. The interactive lesson shows this as a live animation or chart.
Worked example and use case
36 g of water is 2 mol, which contains 1.204 x 10^24 molecules.
Frequently asked questions about Mole
What is Mole?
The amount of substance containing exactly 6.022 x 10^23 elementary entities.
Is Mole a beginner, intermediate or advanced topic?
Mole is a beginner topic in Atomic Structure & Periodicity. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Mole?
Study these earlier topics in Atomic Structure & Periodicity first: Isotones, Relative Atomic Mass, Atomic Mass Unit.
What comes after Mole?
The next topics in Atomic Structure & Periodicity are Avogadro's Number and Molar Mass.
Can I practise Mole with quizzes?
Yes. The interactive lesson includes a self-check question on Mole, and the Atomic Structure & Periodicity quiz draws on every topic in this area.
Where Mole fits in Atomic Structure & Periodicity
Mole is topic 26 of 115 in Atomic Structure & Periodicity.