2.1.A—Describe the properties and interactions of a system

Describe the properties and interactions of a system.

• System properties are determined by the interactions between objects within the system.
• If the properties or interactions of the constituent objects within a system are not important in modeling the behavior of the macroscopic system, the system can itself be treated as a single object.
• Systems may allow interactions between constituent parts of the system and the environment, which may result in the transfer of energy or mass.
• Individual objects within a chosen system may behave differently from each other as well as from the system as a whole.
• The internal structure of a system affects the analysis of that system.
• As variables external to a system are changed, the system’s substructure may change.