Mendeleev · science lesson
The mole: counting without counting
The mole links a measurable macroscopic amount to an exact number of microscopic entities.
Start with the idea
The mole links a measurable macroscopic amount to an exact number of microscopic entities.
A concrete example
0.50 mol corresponds to 0.50 × Nₐ specified entities. You should always state which entities are being counted.
Practical method
Go one step deeper
With Nₐ = 6.02214076 × 10²³ mol⁻¹ exactly, 0.50 mol represents 3.01107038 × 10²³ specified entities.
Common trap
A trend or model is not an exceptionless law. Always check the quantity’s definition and the conditions being compared.
Check your understanding
Can you explain the phenomenon in your own words before looking at an equation?