What type of system can exchange neither energy nor matter with its surroundings?

An isolated system is defined as one that does not exchange either energy or matter with its surroundings. This means that all processes taking place within the system are completely contained, with no heat transfer, work done on or by the system, or mass crossing its boundaries.

In thermodynamics, the significance of an isolated system lies in the First Law of Thermodynamics, which states that energy within an isolated system is conserved. This means that the total energy of the system remains constant over time, as no energy can enter or leave it.

In contrast, an open system can exchange both energy and matter with its surroundings, while a closed system can exchange energy but not matter. A diathermic system, on the other hand, allows heat exchange but not matter exchange, making it distinct from an isolated system's characteristics.

The importance of identifying an isolated system is crucial in understanding idealized models in thermodynamics, such as analyzing processes without external influences affecting the system's energy and mass.