Question

What is an isolated system?

Answer 1

We have three types of systems: closed system, open system, an isolated system. A system in thermodynamics represents the part of the universe in which observations are made. In an isolated system, there is no exchange of heat and energy between the surroundings and the system.

Complete answer:
To understand an isolated system we will define some thermodynamic terms.
System- It is the part of the universe in which all observation can be done called a system.
Surrounding- Other than a system in-universe all is surrounding.
Universe- System, and surroundings make the universe.
We have three kinds of systems-
Before defining the system let us understand what the boundary is. A boundary is that wall that separates the system from its surroundings.
Open system- In an open system, there is an exchange of energy and matter between the surrounding and system called an open system. For example, Water in a glass, tea in a cup.
Closed system- In the closed system there is an exchange of heat or energy but no exchange in matter called a closed system. For example water bottles etc.
The isolated system-In an isolated system there is no exchange of heat or energy as well as matter with the surrounding. For example thermos flask, insulated vessel.
There are two ways to make such a system-
1. The system may be so far away from another system that they cannot interact with each other.
2. The system can be encased in such a way that neither energy nor mass can enter or exit.

Note:
Isolated system obeys energy conversion law. An isolated system differs from a closed system by the transfer of energy. Closed systems are closed only to the matter, energy can be exchanged at the boundaries of the system. Thermos flask or any other closed insulated vessel is an example of an isolated system.