TS 1516 ISO 31-8

TS 1516 ISO 31-8 is a terminology standard within the SI framework for the names and symbols of quantities and units used in physical chemistry and molecular physics. It helps present technical information in a consistent way, so the same quantity is identified clearly across scientific writing, calculations and documentation.

According to the scope, the standard covers names and symbols for quantities and units in these fields, and where appropriate it also gives conversion factors. In general technical terms, physical chemistry deals with quantities linked to matter, energy, equilibrium, solutions and reactions, while molecular physics focuses on behaviour at the scale of atoms and molecules. That distinction matters because many symbols are shared across disciplines, but their context determines how they are interpreted.

How the terminology framework is used

The value of a standard like this lies in reducing ambiguity. By aligning nomenclature and symbols, it supports clearer communication when a quantity may appear in more than one form or unit system. For users working with physical chemistry and molecular physics, this kind of reference helps maintain consistency in equations, tables, laboratory records and educational material without changing the underlying science.

What this part contributes

• Defines names and symbols for quantities and units in physical chemistry and molecular physics.
• Includes conversion factors where appropriate.
• Supports consistent notation across scientific and technical documents.
• Fits into the broader ISO 31 quantities-and-units structure as a specialized vocabulary section.