Final answer:
A system is a part of the universe under study, such as a beaker or a flask. An isolated system does not allow a transfer of energy or matter. It is similar to a closed, insulated thermos bottle.
Step-by-step explanation:
In the study of energy, we use the term system to describe the part of the universe under study: a beaker, a flask, or a container whose contents are being observed and measured. An isolated system is a system that does not allow a transfer of energy or matter into or out of the system. A good approximation of an isolated system is a closed, insulated thermos-type bottle. The fact that the thermos-type bottle is closed keeps matter from moving in or out, and the fact that it is insulated keeps energy from moving in or