Which description fits an isolated system?

An isolated system is defined as one that does not exchange either matter or energy with its surroundings. This means that within the boundaries of the system, all processes occur without any input or output from the external environment. In physics and thermodynamics, this concept is crucial for understanding various processes, as it allows for the analysis of the system's internal changes without considering external influences or resources.

In contrast, other descriptions imply some form of interaction with the environment. For instance, a system with unlimited energy sources suggests an energy exchange, while a system that exchanges both matter and energy directly contradicts the definition of being isolated. Additionally, a system that is connected with external environments indicates that it is open to both matter and energy flows, which again is at odds with the characteristics of an isolated system.

Understanding these distinctions is vital in environmental systems and societies, as it allows for proper categorization of systems according to how they function and interact with their surroundings.