Question

Which of the following is an example of a closed system?

An estuary where fresh and ocean water mix
A chemical reaction within deep ocean organisms allowing them to glow
A living single-celled organism such as a phytoplankton
A river that flows into the ocean

Answer 1

Hello there :)

Which of the following is an example of a closed system?

Answer:

A chemical reaction within deep ocean organisms allowing them to glow

Answer 2

The answer for the given question above would be the second option. The one that is an example of a closed system is a chemical reaction within deep ocean organisms allowing them to glow. By definition, a closed system is a system that doesn't exchange any matter with its surroundings. Hope this answers your question.