Open System

Open System

An open system can exchange both matter and energy with its surroundings.

Think of a beaker of water on a table. Water molecules evaporate into the air (matter leaving), and heat flows from the room into the water (energy entering). The boundary here is the imaginary surface that encloses the beaker and its contents. The beaker's walls are a real physical boundary, but the top surface is an imaginary one through which matter and energy pass freely. …