Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
A closed system refers to a physical system that does not exchange matter with its surroundings but can exchange energy with them. In other words, no mass enters or leaves the system, but energy can be transferred in or out.
Related terms
Isolated System: An isolated system is similar to a closed system but does not allow any transfer of energy with its surroundings.
As mentioned earlier, conservation laws apply to closed systems where certain physical quantities remain constant over time.
Energy Transfer Mechanisms: These mechanisms include processes such as conduction, convection, and radiation through which energy can be exchanged between a closed system and its surroundings.