Answer: Open System
Explanation: System can be classified into 3 types-
a) Open System - In this kind of system, matter and energy both are exchanged freely with the surroundings.
Example - A tea in a container with the open lid.
b) Closed System - In this kind of system, matter cannot be exchanged but energy can be exchange with the surroundings.
Example - A tea in the container with closed lid.
c) Isolated System - In this, neither energy or matter can be exchanged with the surroundings.
Example - A tea in an insulated thermal flask.
Thus the system in which matter and energy are exhanged freely between the syste and the surroundings is classiifed as Open System.
