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Summary After the revision of the International System of Units (SI), the mole (the SI unit of amount of substance) is based on a fixed number of specified entities. This number is the fixed numerical value of the Avogadro constant NA. Experiments for the practical realization of the mole on a primary level are described independently of their definition in a so‐called "mise en pratique". Traceability of a chemical quantity to the unit mole requires – as before – a measurement procedure with which the analyte can be identified and quantified. The revised definition has no consequences for measurement results in chemistry neither for precision measurements such as isotope dilution mass spectrometry (IDMS) nor for any other method used for realising traceability to the SI. Any practical work in chemistry, for example measurement results of routine laboratories is, hence, unaffected by the revision of the SI System. [ABSTRACT FROM AUTHOR]