Final answer:
An isolated system is a system that can exchange neither energy nor matter with its surroundings. It is completely separated from its environment and does not allow any transfer of energy or matter into or out of the system.
Step-by-step explanation:
An isolated system is a system that can exchange neither energy nor matter with its surroundings. It is completely separated from its environment and does not allow any transfer of energy or matter into or out of the system.
A good example of an isolated system is a closed, insulated thermos-type bottle. The fact that the bottle is closed keeps matter from moving in or out, and the fact that it is insulated keeps energy from moving in or out as well.
An isolated system does not actually exist in reality because some energy is always exchanged between a system and its surroundings, although this process may take place very slowly.