Question

open and closed systems

why are closed systems considered theoretical models?

they are systems that are not fully understood by environmental scientists.

they are very common to see in nature and most ecosystems are examples.

closed systems dont exchange anything with their surroundings and rarely occur.

Explanation:

Closed systems are isolated and self - contained, lacking interactions with other systems. They don't exchange energy, matter, or information with their surroundings. In nature, most systems are open (like ecosystems). Closed systems rarely occur naturally, which is why they are theoretical models.

Answer:

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