Avogadro constant
The mole is linked to a specified number of entities.
Key knowledge
The Avogadro constant N_A is exactly 6.022 140 76 × 10²³ mol⁻¹ by the SI definition. An amount of one mole contains that number of specified elementary entities.
Reference values
N_A6.02214076e23mol⁻¹
Exact value · SI definitionValues and equations
N_A = 6.022 140 76 × 10²³ mol⁻¹
- N_A
- Avogadro constant mol⁻¹
Conditions and scope
- Specify the entities being counted, such as atoms, molecules or ions.
- Exact definition does not make a practical sample's amount or composition exact.
Sources · 5
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Bureau International des Poids et Mesures (BIPM)3 sources
- SI defining constantsBureau International des Poids et Mesures (BIPM)Reference guide
- The International System of Units, ninth edition, version 4.01 (2026)Bureau International des Poids et Mesures (BIPM)Reference guide
- The International System of Units, 9th edition, version 4.01 (2026)Bureau International des Poids et Mesures (BIPM)Reference guide
- Meet the ConstantsNational Institute of Standards and Technology (NIST)Reference guide
- 国際単位系(SI)第9版 · Japanese translation, V3.01National Metrology Institute of Japan, AISTReference guide · PDF
Evidence and review
BIPM constant table and SI Brochure mole definition; NIST Avogadro comparison.
2026-10-10 · Exact value, reciprocal-mole unit and specified-entity requirement only.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Agreement within this scope
Avogadro’s constant is exactly 6.02214076×10^23 mol−1 and the entities must be specified.
Entity counting and practical amount-of-substance determination still carry uncertainty.
National Metrology Institute of Japan, AIST
- 国際単位系(SI)第9版 · Japanese translation, V3.01 JapanJapaneseShared standard
2.3.1 Mole, pp18–19
- 国際単位系(SI)第9版 · Japanese translation, V3.01
Entry details
Permanent link to this entry ↗- Record identity
- si-avogadro-constant
- Revision
- core.1
- Structured reference record
- SI