Summary:
- The International System of Units is a system of measurement based on the metric system.
- The metric system was originally established in France in 1795.
- The SI was adopted by international agreement in 1960 and is composed of seven base units.
- Five of these units are commonly used in chemistry.
- All other measurement quantities, such as volume, force, and energy, can be derived from these seven units.
- The map in Figure below shows the adoption of the SI units in countries around the world.
- The United States has legally adopted the metricsystem for measurements, but does not use it in everyday practice.