SI Units

Mol

Definição

A unidade de base do SI para quantidade de matéria, definida como exatamente 6,02214076 × 10²³ entidades elementares (átomos, moléculas, íons, etc.).

Explicação

One mole of carbon-12 atoms has a mass of exactly 12 grams. The number 6.02214076×10²³ is Avogadro's number, fixed by the 2019 SI redefinition. A mole of water molecules (18 g) fits in about 18 mL — a tablespoon. Chemists use moles because atoms are too small to count individually, but a mole provides a practical laboratory-scale quantity.

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RELATED TERMS

Metro

A unidade de comprimento de base do SI, definida como a distância que a luz percorre em 1/299.792.458 de segundo.

Quilograma

A unidade de massa de base do SI, definida por meio da constante de Planck.

Segundo

A unidade de tempo de base do SI, definida com base nas oscilações do átomo de césio-133.

Kelvin

A unidade de temperatura termodinâmica de base do SI, cujo ponto de origem é o zero absoluto.

Ampere

A unidade de corrente elétrica de base do SI.