Question

why are closed systems considered theoretical models? they are very common to see in nature and most ecosystems are examples. they are systems that are not fully understood by environmental scientists. closed systems don’t exchange anything with their surroundings and rarely occur.

Explanation:

A closed - system is defined as a system that does not exchange matter with its surroundings, only energy. In reality, such systems rarely occur as it's difficult to completely isolate a system from matter exchange. Thus, they are considered theoretical models.

Answer:

Closed systems don't exchange anything with their surroundings and rarely occur.